BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Microscopic Dynamics of Structural Glasses Investigated by Quasiel astic Neutron Scattering DTSTART;VALUE=DATE-TIME:20220902T070000Z DTEND;VALUE=DATE-TIME:20220902T074000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3701@indico.stfc.ac.uk DESCRIPTION:Speakers: Reiner Zorn (Forschungszentrum Juelich)\nIn this pre sentation I will give a short introduction into quasielastic neutron scatt ering (QENS) and its application to glass-forming systems. QENS operates o n time scales from picoseconds to a microsecond and at the same time has a spatial resolution in the Ångström range. Therefore\, it is well suited for the study of molecular and polymeric glass-formers.\n\nThe dynamics o f glass-formers is still poorly understood\, but certain universal feature s can be found which a theory has to explain. Foremost\, there is the α r elaxation\, which governs what is usually called ‘glass transition’. I ts temperature-dependence is highly non-Arrhenius and the shape of correla tion functions non-exponential. In addition\, faster relaxations may be pr esent\, among which the universal ‘fast β relaxation’ in the picoseco nd range is strongly related to the α relaxation in mode-coupling theory. As the fastest universal process\, glasses show an excess of the vibratio nal density of states above the Debye model in the low frequency range\, t he so-called ‘boson peak’.\n\nAll these phenomena can be observed by Q ENS with the additional information of a length scale. In addition\, it is possible to study them in confined glass-formers in order to access their system-size-dependence. Selected QENS experiments will be presented and d iscussed.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3701/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3701/ END:VEVENT BEGIN:VEVENT SUMMARY:Status of the Swiss Muon Source at PSI DTSTART;VALUE=DATE-TIME:20220830T135000Z DTEND;VALUE=DATE-TIME:20220830T140500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3687@indico.stfc.ac.uk DESCRIPTION:Speakers: Thomas Prokscha (Paul Scherrer Institute)\nThe Labor atory for Muon Spin Spectroscopy (LMU) at PSI develops and operates the si x muon instruments of the Swiss Muon Source (SμS). We give an overview of the current status\, with an update on the commissioning of the new FLAME instrument and the upgrade plan of the μE4 beamline to increase the rate of low-energy muons by 50% in 2025. Furthermore\, a new experimental faci lity is under development: the Muon-Induced-Xray-Emission (MIXE) instrumen t using negative muons for non-destructive\, depth-selective elemental ana lysis of archeological artefacts\, extraterrestrial samples and for operan do studies of devices.\n\nOn a longer term\, PSI is planning the major upg rade project IMPACT of the High-Intensity Proton Accelerator (HIPA). IMPAC T ("Isotope and Muon Production using Advanced Cyclotron and Target techno logies") aims for the production of radioactive isotopes for cancer diagno sis and therapy\, and the installation of HIMB\, the two "High Intensity M uon Beams". HIMB involves the replacement of the existing target M and the two beamlines πM1 and πM3 by a new target H with two very high-intensit y surface muon beamlines μH2 and μH3 with muon rates up to 1010/s. This will offer unique new possibilities for muon applications [1]. Installatio n of this major facility upgrade is foreseen in a 1.5 years shutdown in 20 27/2028. The project proposal is currently being under evaluation.\n\n[1] M. Aiba et al.\, Science Case for the new High-Intensity Muon Beams HIMB a t PSI\, arXiv:2111.05788.\n\nhttps://indico.stfc.ac.uk/event/53/contributi ons/3687/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3687/ END:VEVENT BEGIN:VEVENT SUMMARY:Coherent microwave control of muonium DTSTART;VALUE=DATE-TIME:20220901T144000Z DTEND;VALUE=DATE-TIME:20220901T150000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3656@indico.stfc.ac.uk DESCRIPTION:Speakers: Andrin Doll (Paul Scherrer Institute)\nWe demonstrat e the most fundamental coherent control techniques by excitation of microw ave spin transitions in muonium\, namely driven Rabi oscillations and Rams ey fringes upon free evolution. Unprecedented performance is achieved by t riggering microwave pulses by a single implanted muon\, which enables cohe rent spin manipulation of individual muonium atoms.\n\nAs a first example\ , we suppress extrinsic line broadening with the Ramsey experiment on stro ngly coupled muonium in SiO$_2$ (Fig. 1). As a second example\, we retriev e the electron $g$-factor of bond-centered muonium in Si using the double electron-muon resonance (DEMUR) technique and decouple the system from its environment by strong driving of the electron-muon double quantum transit ion.\n\nOverall\, we expect that this capability will provide a powerful t ool to investigate the effect of the environment on isolated coupled spins \, uncover the details of coupled electron-muon systems in matter and vali date quantum electrodynamics in the context of (vacuum) muonium spectrosco py.\n\n![Microwave experiments with muonium formed in SiO$_2$ at 280 K\, s howing Rabi oscillations excited by 3.6 GHz microwaves (left) and phase-co herent Ramsey fringes excited by 30 ns pulses (right). The upper schemes d epict the timing of the experiment.][1]\n\n\n [1]: https://drive.switch.c h/index.php/s/ldNpkYnVkvrkP6m/download\n\nhttps://indico.stfc.ac.uk/event/ 53/contributions/3656/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3656/ END:VEVENT BEGIN:VEVENT SUMMARY:New insight into $\\mu$SR in water DTSTART;VALUE=DATE-TIME:20220902T090000Z DTEND;VALUE=DATE-TIME:20220902T092000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3629@indico.stfc.ac.uk DESCRIPTION:Speakers: Amba Datt Pant (IMSS\, KEK\, Japan)\nOver the past f our decades\, muon spin rotation and relaxation technique in water and ice has been reported by several groups [1-4]. Most of the previous studies w ere focused on muonium chemistry (detection\, its relaxation\, reaction an d frequencies) in water and ice. To deepen the understanding of muon behav ior in water and application of $\\mu$SR to life sciences and hydrated sam ples\, we performed temperature dependent $\\mu$SR study in water. We foun d the temperature dependent oscillation in zero-field spectra in ice for t he first time and proposed a new model – interaction between four spin-o ne-half system – to interpret the data. We found two stopping sites (pro portion of 35% and 10% of incident muons) for muons in hexagonal ice in wh ich the muons in larger fraction (35%) move towards optimized geometry sit e with temperature approaching the melting point. The distances of the muo n and protons are successfully detected in subatomic scale. This study wil l be helpful to understand the charge dynamics in materials\, for example\ , ion diffusion in battery materials\, proton transfer in hydrated materia ls\, proton transfer in biological membranes and in general transport of o ther spin-nuclei in solid state materials.\n\n[1] P. W. Percival\, et al.\ , *Chem. Phys. Lett*. **39** (1976) 333\; *Hyperfine Interact*. **8** (198 1) 325\; *Hyperfine Interact*. **18** (1984) 543\; *Chem. Phys*. **32** (1 978) 353\; *Chem. Phys*. **95** (1985) 321.\n[2] K. Nagamine\, et al.\, *C hem. Phys. Lett*. **87** (1982) 186.\n[3] S. Cox\, et al.\, *Hyperfine Int eract*. **65** (1991) 993\; *Physica Scripta* **1992** (1992) 292\; *Hyper fine Interact*. **86** (1994) 747.\n[4] Y. Wang\, et al.\, *Physica B: Con densed Matter* **350** (2004) E451.\n\nhttps://indico.stfc.ac.uk/event/53/ contributions/3629/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3629/ END:VEVENT BEGIN:VEVENT SUMMARY:Sponsor Event: Quantum Design DTSTART;VALUE=DATE-TIME:20220830T092000Z DTEND;VALUE=DATE-TIME:20220830T093000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3855@indico.stfc.ac.uk DESCRIPTION:Speakers: Simone Paziani ()\nPresentation by Simone Paziani\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3855/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3855/ END:VEVENT BEGIN:VEVENT SUMMARY:Sponsor Event: CAEN-Nuclear Instruments DTSTART;VALUE=DATE-TIME:20220830T130500Z DTEND;VALUE=DATE-TIME:20220830T131500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3856@indico.stfc.ac.uk DESCRIPTION:Speakers: Andrea Abba ()\nPresentation by Andrea Abba\n\nhttps ://indico.stfc.ac.uk/event/53/contributions/3856/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3856/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of non-destructive and depth-selective quantification method of sub-percent carbon contents in steel by negative muon lifetime m easurement DTSTART;VALUE=DATE-TIME:20220830T152000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3875@indico.stfc.ac.uk DESCRIPTION:Speakers: I-Huan Chiu (Osaka University)\nWhen a negatively ch arged muon stops in a material\, the muon makes muon atomic orbitals aroun d an atomic nucleus in the material. The muon orbiting its 1s orbital is a bsorbed into the nucleus with a mean lifetime depending on the atomic numb er of the nucleus (Z). This no-electron-emission process competes with the natural decay of the muon into an electron with a lifetime of 2.2 μs. Th e nuclear absorption rate becomes faster as Z increases. The apparent life time of the muons gets shorter with Z\; e. g. 2.0 μs in carbon and 0.20 μs in iron. It is possible to identify the element that captured a muon b y measuring the lifetime. A　compound's elemental composition can be non- destructively determined by measuring the electron lifetime spectrum. We h ave conducted a feasibility study on the non-destructive identification of carbon contents in steel (iron-containing carbon).\nThe muon experiment w as conducted at the D1 area of the Muon Science Establishment in the Japan Proton Accelerator Research Complex (J-PARC MUSE). The decay electrons we re measured by the large-solid angle plastic scintillation counter system Kalliope for μSR. Standard steel samples with known carbon content were u sed for obtaining a calibration curve. A stacked steel sample consisting o f three steel plates with carbon contents of 0.51%\, 0.20% and 1.03 % of 0 .5 mm in thickness was irradiated by three different muon beam momenta to stop muons in the middle of each layer.\nThe lifetime spectrum was fitted by four components\; iron\, carbon\, air (N\, O and Ar) and a long-lifetim e background. The carbon contents in the stacked sample determined by the lifetime spectra agreed well with the known carbon contents in each steel layer. In summary\, we successfully demonstrated the non-destructive and d epth-selective determination of sub-percent carbon contents in steel by mu on lifetime measurement.\n\nhttps://indico.stfc.ac.uk/event/53/contributio ns/3875/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3875/ END:VEVENT BEGIN:VEVENT SUMMARY:The internal magnetic field in a ferromagnetic compound Y$_2$Co$_{ 12}$P$_7$ DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3753@indico.stfc.ac.uk DESCRIPTION:Speakers: Kazuki Ohishi (CROSS Neutron Science and Technology Center)\nVarious $\\mu^+$SR techniques have been widely used for studying internal magnetic fields in assorted materials [1]\, such as\, antiferroma gnets\, spin-glasses\, paramagnets\, and superconductors. However\, for fe rromagnetic (FM) materials\, $\\mu^+$SR faces a difficulty in determining the correct dipole field at the muon site $({\\bf H}_{\\rm dip})$ because the internal magnetic field at the muon site in ferromagnets is expressed by\; ${\\bf H}_{\\mu}={\\bf H}_{\\rm dip}~+~{\\bf H}_{\\rm L}~+~{\\bf H}_{ \\rm hf}$\, where ${\\bf H}_{\\rm L}$ is the Lorentz field and ${\\bf H}_{ \\rm hf}$ is the hyperfine field at the muon site. Therefore\, the muon si tes and the magnetic structure need to be apprehended for evaluating ${\\b f H}_{\\rm dip}$ but also the saturation magnetization for evaluating ${\\ bf H}_{\\rm L}$ and the local spin density at the muon site for evaluating ${\\bf H}_{\\rm hf}$.\n\nConsidering the three contributions to ${\\bf H} _{\\rm \\mu}$ in the above equation\, a combined work with $\\mu^+$SR and DFT calculations are needed to provide a reasonable estimate for the order ed magnetic moment of rare earth ($R$) ions in ${\\rm Nd}_2{\\rm Fe}_{14}{ \\rm B}$ and related magnets [2]. Following upon this work\, we attempt to estimate the ordered magnetic moments of $R$ ions in cobalt-based FM mate rials\, $R_2{\\rm Co}_{12}{\\rm P}_7$ with such combined work. As a first step\, a powder sample of $R_2{\\rm Co}_{12}{\\rm P}_7$ with $R={\\rm Y}$ was measured with $\\mu^+$SR and three clear muon spin precession signals below its Curie temperature ($T_{\\rm C}=151~$K) were found.\n\n[1] A. Yao uanc and P. D. de R$\\acute{\\rm e}$otier\, ``Muon Spin Rotation\, Relaxat ion\, and Resonance\, Application to Condensed Matter" (Oxford\, New York\ , 2011).\n\n[2] J. Sugiyama et al.\, Phys. Rev. Material ${\\bf3}$\, 06440 2 (2019).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3753/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3753/ END:VEVENT BEGIN:VEVENT SUMMARY:Quantum Information: How does it μve through fluorides? DTSTART;VALUE=DATE-TIME:20220831T074000Z DTEND;VALUE=DATE-TIME:20220831T080000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3623@indico.stfc.ac.uk DESCRIPTION:Speakers: John Wilkinson (STFC)\nThe unitary evolution of a qu antum system preserves its coherence\, but interactions between the system and its environment result in decoherence\, a process in which the quantu m information stored in the system becomes degraded. A spin-polarized posi tively charged muon implanted in a fluoride crystal realizes such a cohere nt quantum system\, and the entanglement of muon and nearest-neighbor fluo rine nuclear spins gives rise to an oscillatory time dependence of the muo n polarization that can be detected and measured. In this talk\, we will s how that the decohering effect of more distant nuclear spins can be modell ed quantitatively\, allowing a very detailed description of the decoherenc e processes coupling the muon-fluorine “system” with its “environmen t\,” and allowing us to track the system entropy as the quantum informat ion degrades [1]. Examples of this approach to various fluorides will be p resented\, using these methods to gain knowledge of the nature of the muon stopping site\, distinguish between different crystalline phases of a com pound\, and identify Frenkel defects [2].\n\n**References**\n[1] J. M. Wil kinson and S. J. Blundell\, *Phys. Rev. Lett.*\, **125** 087201 (2020).\n[ 2] J. M. Wilkinson et al.\, *Phys. Rev. B*\, **89** L220409 (2021).\n\nhtt ps://indico.stfc.ac.uk/event/53/contributions/3623/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3623/ END:VEVENT BEGIN:VEVENT SUMMARY:Ultrafast molecular rotors in metal-organic frameworks: a combined $^{1}$H-NMR and $\\mu$SR study DTSTART;VALUE=DATE-TIME:20220830T080000Z DTEND;VALUE=DATE-TIME:20220830T082000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3631@indico.stfc.ac.uk DESCRIPTION:Speakers: Giacomo Prando (Dipartimento di Fisica\, Università degli Studi di Pavia\, Italia)\nTypically\, the solid state is not well s uited to sustaining fast molecular motion - however\, in recent years a va riety of molecular machines\, switches and rotors have been successfully e ngineered within porous crystals and on surfaces. Here\, we report on a co mbined $^{1}$H-NMR [1] and $\\mu$SR [2] study of fast-rotating molecular r otors within the bicyclopentane-dicarboxylate struts of a zinc-based metal -organic framework. Here\, the carboxylate groups anchored to the metal cl usters act as an axle while the bicyclic units are free to rotate. The thr ee-fold bipyramidal symmetry of the rotator conflicts with the four-fold s ymmetry of the struts\, frustrating the formation of stable conformations and favouring the continuous\, unidirectional\, ultrafast rotation of the bicyclic units down to cryogenic temperatures. As a remarkable consequence \, the fast-motions regime for the $^{1}$H-NMR spin-lattice relaxation rat e is maintained down to at least 2 K\, as confirmed by its dependence on t emperature and magnetic field. These results are confirmed by zero-field a nd longitudinal-field $\\mu$SR experiments and\, in particular\, by the de pendence of the longitudinal relaxation rate on temperature. At the same t ime\, the experimental evidences suggest several implantation sites for th e muons\, among which one directly onto the rotating moiety. Muons thermal ized in this latter site generate clear oscillations in the depolarization (shown in the picture) resulting from the dipolar interaction with the $^ {1}$H nuclear moments on the rotors. We evidence a highly unusual dependen ce of these oscillations on temperature\, suggesting a complex influence o f the rotations on the muon implantation and diffusion.\n\n![Evidence of a H-$\\mu$-like state on the rotating moiety at low temperatures.][3]\n\n[1 ] J. Perego *et al.*\, *Nature Chemistry* **12** 845 (2020).\n\n[2] G. Pra ndo *et al.*\, *Nano Letters* **20** 7613 (2020).\n\n[3]: http://nmrphysic s.unipv.it/wp-content/uploads/2022/07/Rotors.jpg\n\nhttps://indico.stfc.ac .uk/event/53/contributions/3631/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3631/ END:VEVENT BEGIN:VEVENT SUMMARY:Low energy muon study of the p-n interface in chalcopyrite solar c ells DTSTART;VALUE=DATE-TIME:20220830T095000Z DTEND;VALUE=DATE-TIME:20220830T101000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3625@indico.stfc.ac.uk DESCRIPTION:Speakers: Helena Vieira Alberto (University of Coimbra\, Portu gal)\nThe slow muons technique provides a quantitative approach to charact erize the effect of various cover layers on the passivation of bulk defect s near the p-n junction of solar cells [1]. \nSeveral cover layers on top of the chalcopyrite Cu(In\,Ga)Se2 (CIGS) semiconductor absorber were inves tigated in this work\, namely CdS\, ZnSnO\, Al2O3 and SiO2. \n\n\nThe figu re shows the depth profile of a measurement on a CdS/CIGS sample. The diam agnetic fraction is used as an indication of the perturbation of the latti ce at the site of the muon. The lower part of the figure shows the model d epth profile obtained after deconvolution of the experimental data with th e range distribution function. The dip in the diamagnetic fraction near th e interface indicates that the lattice is more perturbed in this near-inte rface region than further inward in the sample. We find that CdS provides the best defect passivation\; the oxide materials are less effective.\n\n[ 1] Alberto\, H.V. et al. “Characterization of the interfacial defect lay er in chalcopyrite solar cells by depth resolved muon spin spectroscopy” \, accepted for publication in Advanced Materials Interface\, 2022.\n\n![D epth profile of the diamagnetic fraction for CdS/CIGS. The lower part disp lays the model function used in the fit.][1]\n\n\n [1]: http://algol.fis. uc.pt/muon/CdS_CIGS_Fig.jpg\n\nhttps://indico.stfc.ac.uk/event/53/contribu tions/3625/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3625/ END:VEVENT BEGIN:VEVENT SUMMARY:First depth-resolved beta-NMR measurements of 1-ethyl-3-methylimid azolium acetate DTSTART;VALUE=DATE-TIME:20220902T074000Z DTEND;VALUE=DATE-TIME:20220902T080000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3630@indico.stfc.ac.uk DESCRIPTION:Speakers: Derek Fujimoto (TRIUMF)\nOver the past decade\, we h ave been using beta-detected NMR to examine the properties of amorphous ma terials. While this has typically focused on polymers\,$^1$ we have recent ly been interested in ionic liquids (ILs). ILs are binary mixtures: they a re composed of two oppositely charged molecular species. They are also liq uid at room temperature. Their properties\, determined by strong electrost atic forces\, make them attractive candidates for the development of next- generation battery technology.\n\nThe long-range forces between ions also affect their dynamics\, one of our primary interests in amorphous material s. This makes ILs a fascinating comparison to the relatively well-understo od case of polymers. As with polymers\, many ILs are extremely resistant t o crystallization and will instead vitrify upon cooling. In our prior work \, we showed that $\\beta$-NMR was a good probe of bulk IL dynamics and dy namic heterogeneity.$^2$ In our present experiments\, we turn to the quest ion of how the surface modifies these properties\, presenting the first de pth-resolved $\\beta$-NMR measurements in 1-ethyl-3-methylimidazolium acet ate. This interfacial region is important for understanding how constraine d dimensionality affects dynamics\, which in turn may affect this IL's eff ectiveness as a potential electrolyte in batteries or capacitors.\n\nWe wi ll show that both the surface and the glass transition have large effects on molecular dynamics\, which in many aspects differs greatly from our exp ectations. In the glassy phase\, the surface dynamics appear to be simulta neously faster (i.e.\, liquid-like) and yet still heterogeneous (i.e.\, gl ass-like)\, an apparent departure from our understanding of "normal" behav iour. Additionally\, relaxation becomes faster below the glass transition temperature.\n\n$^1$McKenzie\, I. et al. J. Chem. Phys. 156\, 084903 (2022 ).\n$^2$Fujimoto\, D. et al. Chem. Mater. 31\, 9346–9353 (2019).\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3630/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3630/ END:VEVENT BEGIN:VEVENT SUMMARY:In-flight muon spin resonance and muonium interferometer DTSTART;VALUE=DATE-TIME:20220901T152000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3877@indico.stfc.ac.uk DESCRIPTION:Speakers: Sohtaro Kanda (KEK)\nThe muon and muonium play a uni que role in materials science as a tiny magnetometer and an emulator of hy drogen in matter. However\, there are few examples of their application as matter waves. This is because the surface muon and its simple slowing-dow n in a degrader cannot keep sufficient coherence. Low-energy muons from la ser ionization of muonium can be used to obtain slow muonium with small te mporal and spatial spread. Like an ordinary atomic interferometer\, a muon ium interferometer has a variety of potential applications. For example\, muonium spectroscopy using interference effects\, studies of quantum inter ference effects such as a measurement of Berry phase\, and precise measure ments of fundamental constants will be possible using muonium interferomet ry. In this contribution\, we discuss the in-flight spectroscopy of muoniu m and the potential of muonium interferometry.\n\nhttps://indico.stfc.ac.u k/event/53/contributions/3877/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3877/ END:VEVENT BEGIN:VEVENT SUMMARY:New insights into the photochromism of yttrium oxyhydride thin fil ms from in-situ muon spin rotation (MuSR) and positron annihilation spectr oscopy (PAS) studies DTSTART;VALUE=DATE-TIME:20220830T103000Z DTEND;VALUE=DATE-TIME:20220830T105000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3627@indico.stfc.ac.uk DESCRIPTION:Speakers: Stephan Eijt (Delft University of Technology)\nThin films of rare-earth metal oxyhydrides\, such as yttrium oxyhydrides (YH$_{ 3-2x}$O$_x$)\, show a pronounced photochromic effect where the transparenc y of the films decreases reversibly over a large range of sub-bandgap wave lengths upon exposure to UV light. This makes these materials suitable can didates for applications in smart windows. However\, the exact mechanism b ehind the photochromic effect is unknown. We investigated the behavior of YH$_{3-2x}$O$_x$ thin films\, with different O:H ratios\, under dark and i lluminated conditions using in-situ muon spin relaxation\, employing low e nergy muons at the LEM spectrometer. Transverse Field (TF) measurements\, complemented by ZF and LF experiments\, revealed that the muonium (Mu$^0$) formation\, inferred from the missing fraction in the TF depolarization c urves\, increases with increased O:H ratio corresponding to a larger semic onductor band gap. The temperature dependence of the muonium fraction was well described by a transition-state model\, where Mu$^0$ formation and gr adual Mu$^{+}$ recovery takes place\, accompanied by the formation of a Mu $^+$-O$^{2-}$ complex and a polaron at the Y cation. The activation energy (E$_{A\,dia}$) associated with Mu$^+$ recovery is dependent on lattice re laxation and is lower for thin films of higher H content (E$_{A\,dia}$ $=2 9$–$45$ meV). In-situ illumination further reduces this energy barrier f or all measured oxyhydrides\, suggesting that the photochromic effect invo lves a reversible structural rearrangement during photodarkening. In the l ight of our muon spin rotation studies\, we discuss several proposals for the identity of the light-absorbing species generated by the electron-hole pairs created upon UV illumination\, such as the formation of metallic do mains by H$^-$ diffusion\, hydroxide formation\, color centers\, and dihyd rogen formation. We complement our discussion with recent findings from in -situ positron annihilation studies on similar films\, that suggest that h ydrogen vacancies are formed\, as well as metallic domains that may play a n important role in the mechanism of the photochromic effect.\n\nhttps://i ndico.stfc.ac.uk/event/53/contributions/3627/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3627/ END:VEVENT BEGIN:VEVENT SUMMARY:Ion Diffusion in Na-ion Battery Cathode Material Na$_{0.5}$Mg$_x$N i$_{0.17-x}$Mn$_{0.83}$O$_{2}$ DTSTART;VALUE=DATE-TIME:20220830T105000Z DTEND;VALUE=DATE-TIME:20220830T111000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3628@indico.stfc.ac.uk DESCRIPTION:Speakers: Martin Mansson (KTH Royal Institute of Technology)\n While Li-ion batteries are considered the main candidate for mobile applic ations\, compounds based on lithium’s heavier cousin\, sodium (Na) have also started to receive a lot of attention lately as candidates for future batteries. One reason is that the Li-reserves are limited and if large sc ale energy storage become a reality in our future sustainable society\, we might have to consider alternatives to the Li-ion technology **[1]**. Dur ing last decade\, an increasing number of new Na-battery materials with im proved performance have been discovered and the general interest for sodiu m-based energy storage have increased tremendously. Among the cathode mate rials the 2D layered P2 – Na$_{2/3}$Ni$_{1/3}$Mn$_{2/3}$O$_{2}$ compound **[2\,3]** has shown promising storage capacity and operating voltages ab ove 3.5 V. Unfortunately\, this material displayed very poor cyclability i .e. short battery life times\, directly related to structural transition d uring the charge cycles. A potential remedy was found by partly substituti ng Ni for Mg. The resulting Na$_{0.67}$Ni$_{0.3−x}$Mg$_{x}$Mn$_{0.7}$O$_ {2}$ compound **[4]** also displayed improved Na-ion diffusion rates. In t his study we have investigated the Na-ion self-diffusion by means of muon spin rotation ($\\mu^+$SR) **[5\,6]** for the compound series $0\\le x \\l e 0.07$. We surprisingly find that even a very small amount of Mg substitu tion (x = 0.02) results in the best cycling stability and highest Na-ion m obility **[7]**.\n\n![enter image description here][8]\n[8]: https://www.n eutrons.se/condmat/muSR2022/Na-ion_LQ.jpg\n\n**[1]** G. Alexander\, J.B. G oodenough\, M. Månsson\, et al.\, Physica Scripta 95\, 062501 (2020) \n** [2]** Z. Lu\, et al.\, J. Electrochem. Soc. 148\, A710 (2001)\n**[3]** Z. Lu\, et al.\, J. Electrochem. Soc. 148\, A1225 (2001)\n**[4]** G. Singh\, et al.\, Chem. Mater. 28\, 5087 (2016)\n**[5]** Sugiyama\, Månsson\, Phys . Rev. Lett. 103\, 147601 (2009)\n**[6]** M. Månsson & J. Sugiyama\, Phys . Scr. 88\, 068509 (2013)\n**[7]** Le Anh Ma\, et al.\, Physical Chemistry Chemical Physics 23\, 24478 (2021)\n\nhttps://indico.stfc.ac.uk/event/53/ contributions/3628/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3628/ END:VEVENT BEGIN:VEVENT SUMMARY:Probing the [FeFe]-hydrogenase subsite using muon spectroscopy DTSTART;VALUE=DATE-TIME:20220902T080000Z DTEND;VALUE=DATE-TIME:20220902T082000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3632@indico.stfc.ac.uk DESCRIPTION:Speakers: Joseph Wright (University of East Anglia)\nIn the dr ive to replace fossil fuels with sustainable alternatives\, achieving the reversible interconversion of protons and dihydrogen is a crucial target. The reaction can be carried out readily using platinum-based systems\, but the cost and availability of this precious metal preclude scaling such ap proaches. In nature\, the [FeFe]-hydrogenase enzymes have evolved to perfo rm the very same task at rates that rival platinum electrodes. These syste ms feature a large protein component in addition to a core bioinorganic un it\, the {2Fe2S} subsite. To enable us to produce practical catalysts we n eed to mimic the chemistry carried out by the enzyme: the natural system i tself is too large and sensitive for wide-scale use. Thus understanding t he chemistry of the {2Fe2S} subsite is vital.\n\nCentral to the hydrogen c hemistry carried out by the subsite is its interaction with protons. Probi ng the solution kinetics and electrochemisty of model systems allows us to understand key reactivity of iron hydrides on a timescale as short as one second. However\, much of the most interesting behaviour of these models occurs on much shorter timescale. For example\, the location of the primar y protonation sites is still an open question\, with terminal and bridging hydrides possible candidates along with the sulphur\, carbonyl and cyanid e ligands. Muonium\, as a ‘light’ analogue of H·\, offers the means of studying the structure and dynamics of such chemistry on the nanosecond timescale. The use of the avoided level cross (ALC) technique has now all owed to identify two sites for primarily muonation in this model in the so lid stat\, with density functional theory (DFT) assignment strongly implic ating competing bridging and terminal binding. This unique insight opens u p the possibility of new reaction pathways in both models and the enzyme a s well as demonstrating the wider importance of muon techniques in studyin g reactive organometallic systems.\n\nhttps://indico.stfc.ac.uk/event/53/c ontributions/3632/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3632/ END:VEVENT BEGIN:VEVENT SUMMARY:Advances in biochemical applications of $\\beta$-detected NMR DTSTART;VALUE=DATE-TIME:20220902T084000Z DTEND;VALUE=DATE-TIME:20220902T090000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3633@indico.stfc.ac.uk DESCRIPTION:Speakers: Victoria Karner (TRIUMF)\nSince the implementation o f $\\beta$-detected NMR ($\\beta$-NMR) at TRIUMF\, it has mainly been used to study condensed matter systems ranging from metals to superconductors to topological insulators. In the last few years\, there has been a desir e to extend the applications of $\\beta$-NMR to include the study of bioch emical problems. For a number of metal ions in our body\, such as Mg(II)\ , Zn(II) and Cu(I)\, the absence of convenient physical and spectroscopic properties limits our ability to characterize their role in health and dis ease using conventional techniques\, such as classical NMR. However\, $\\ beta$-NMR has the possibility to help address these gaps in our knowledge by aiding in the elucidation of metal coordination in biomolecules. \n\nIn this presentation\, I demonstrate that we are able to observe $^{31}$Mg b inding to the biomolecule adenosine 5’-triphosphate (ATP) in solution. T he resonance spectrum shows two distinct peaks which indicates that we obs erve not one\, but two distinct complexes between Mg$^{2+}$ and ATP. We id entify these complexes with $^{31}$Mg $\\beta$-NMR complemented by $^{31}$ P NMR and DFT calculations. This represents the first measurement of a $\\ beta$-NMR probe binding to a biomolecule and is an important milestone in applying $\\beta$-NMR to the study of biochemical problems$^1$.\n\n1. R. M . L. McFadden et al.\, Angew. Chem. Intl. Ed. e202207137 (2022)\n\nhttps:/ /indico.stfc.ac.uk/event/53/contributions/3633/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3633/ END:VEVENT BEGIN:VEVENT SUMMARY:Muonium reaction in semiconductors and insulators: the role of the transition state DTSTART;VALUE=DATE-TIME:20220901T122000Z DTEND;VALUE=DATE-TIME:20220901T124000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3634@indico.stfc.ac.uk DESCRIPTION:Speakers: Rui Vilao (CFisUC\, Department of Physics\, Universi ty of Coimbra)\nThe model describes the reaction of atom-like muonium with the host lattice at the end of the implantation trajectory. Reactions of the bare muon with the host or prompt formation of the final states are no t covered by this model. Since these alternative processes are temperature independent\, their maximum contribution can be estimated from the smalle st value that occurs at any given temperature. They can be considered as a temperature-independent "background".\nAt the end of the trajectory\, the muonium has just enough kinetic energy to jump across the potential barri er from one interstitial site to the next. At the top of the barrier\, muo nium is so slow that a strong inelastic interaction\, e.g.\, the excitatio n of a local stretching mode\, can occur and a weakly bound muon-electron configuration\, the transition state\, is formed (see Fig. 1).\n![Muonium is trapped at a shallow minimum (transition state) at the top of the diffu sion barrier. From there\, it can decay thermally activated either to the muonium ground state (e.g. to neutral muonium in tetrahedral configuration ) or to a bound configuration (e.g. to neutral or ionized bond-centered mu onium).][1]\n\n\n [1]: http://algol.fis.uc.pt/muon/transition_state_Fig.j pg\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3634/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3634/ END:VEVENT BEGIN:VEVENT SUMMARY:Probing hydrogen sites and negative hyperfine parameter in semicon ducting BaSi2 by muon spin rotation DTSTART;VALUE=DATE-TIME:20220901T130000Z DTEND;VALUE=DATE-TIME:20220901T132000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3636@indico.stfc.ac.uk DESCRIPTION:Speakers: Kenji Kojima (TRIUMF and SBQMI\, UBC)\nHydrogen pass ivation of defects is commonly used to reduce defects in semiconductors su ch as GaAs\, diamond\, and Si. We recently found by experiment that atomic hydrogen is also very effective in significantly increasing a minority-ca rrier lifetime (> 10 μs) in BaSi2\, one of the emerging materials for thi n-film solar cell applications. This means that defects no longer act as r ecombination centers in BaSi2 after hydrogen passivation [1-2]. But three has been no experimental data about the hydrogen site in BaSi2. We employe d muons to study the hydrogen state in single-crystalline BaSi2. Distinct neutral muonium state was identified in the high transverse-field measurem ents. From the temperature dependence\, negative hyperfine parameters was suggested. From the angle-dependence of the hyperfine parameter in the mag netic fields applied in the a x b\, b x c\, and c x a planes\, and compari son to the calculations based on density-functional theory (DFT)\, the hyd rogen site in the BaSi2 crystal is proposed.\n[1] Z. Xu et al.\, Phys. Rev . Mater. 3\, 065403 (2019).\n[2] X. Xu et al.\, J. Appl. Phys. 127\, 23310 4 (2020).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3636/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3636/ END:VEVENT BEGIN:VEVENT SUMMARY:Studying spin diffusion and quantum entanglement with LF-$\\mu$SR DTSTART;VALUE=DATE-TIME:20220829T090000Z DTEND;VALUE=DATE-TIME:20220829T092000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3639@indico.stfc.ac.uk DESCRIPTION:Speakers: Francis Pratt (STFC)\nLF-$\\mu$SR studies of spin di ffusion started with mobile solitons [1] and polarons [2] in conducting po lymers. Spin 1/2 antiferromagnetic chains can also support diffusive spin excitations in a certain parameter range of the XXZ model [3]\, showing ei ther diffusive [4] or ballistic transport [5]. Recent LF-$\\mu$SR studies of layered triangular lattice quantum spin liquid materials such as 1T-TaS $_2$ [6] and YbZnGaO$_4$ [7] have shown spin dynamics that is extremely we ll described by a 2D spin diffusion model\, fitting much better than previ ously proposed models for spin correlations. In YbZnGaO$_4$ the diffusion rate shows a clear crossover between classical and quantum regimes as $T$ falls below the exchange coupling $J$. That the spin diffusion approach wo rks well in the high $T$ classical region might be expected\, but it is fo und that it also works equally well in the low $T$ quantum region. This al lows a $T$ dependent length scale to be derived from the data that can be assigned to a quantum entanglement length $\\xi$. Another entanglement mea sure\, the Quantum Fisher Information $F_Q$ [8] can also be obtained from the LF-$\\mu$SR data and compared with $\\xi$.\n\n\n[1] K. Nagamine et al\ , Phys. Rev. Lett. 53\, 1763 (1984)\; [2] F.L. Pratt et al\, Phys. Rev. Le tt. 79\, 2855 (1997)\; F.L. Pratt et al\, Physica B 326\, 34 (2003)\; [3] B. Bertini et al\, Rev. Mod. Phys. 93\, 025003 (2021)\; [4] F.L. Pratt et al\, Phys. Rev. Lett. 96\, 247203 (2006)\; F. Xiao et al\, Phys. Rev. B 91 \, 144417 (2015)\; [5] T. Lancaster et al\, Phys. Rev. B 85\, 184404 (2012 )\; B.M. Huddart et al\, Phys. Rev. B 103\, L060405 (2021)\; [6] S. Manas- Valero et al\, npj Quantum Mater. 6\, 69 (2021)\; [7] F.L. Pratt et al\, P hys. Rev. B 106\, L060401 (2022)\; [8] P. Hauke et al\, Nat. Phys. 12\, 77 8 (2016).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3639/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3639/ END:VEVENT BEGIN:VEVENT SUMMARY:Muonium states in semiconducting transition metal dichalcogenides DTSTART;VALUE=DATE-TIME:20220901T124000Z DTEND;VALUE=DATE-TIME:20220901T130000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3635@indico.stfc.ac.uk DESCRIPTION:Speakers: Jonas A. Krieger (Max Planck Institute of Microstruc ture Physics)\nThe usual response of muonium to an external magnetic field is dominated by the hyperfine interaction\, which causes the observed spe ctrum to show the transition frequencies between different muonium spin st ates. However\, we have recently discovered an unconventional magnetic muo nium state in 2H-MoTe$_2$ where the muonium acts a magnetic impurity\, whi ch polarizes the local electronic magnetic moments $[1]$. For sufficiently small externally applied fields\, the "magnetic" muonium effectively beha ves as a diamagnetic muon in a local magnetic field. Here\, we show experi mentally that in 2H-MoTe$_2$ the magnetic muonium coexists with another co nventional\, non-magnetic muonium state (Fig. 1b). The latter is axially s ymmetric with a hyperfine coupling of A$_\\parallel$=1426(1) MHz and A$_\\ perp$=1368(3) MHz\, corresponding to an effective Bohr radius of $\\approx $ 0.82 Angstrom. The hyperfine coupling remains fairly constant\, as a fun ction of temperature\, until the state disappears around the same temperat ure where the magnetic muonium disappears as well. We employ density funct ional theory calculations to reveal that this is linked to the presence of two muonium sites in the compound: one within the van der Waals gap that becomes magnetic\, and a second one inside the layer\, that is conventiona l. A similar behavior is also observed in 2H-WSe$_2$ (Fig. 1a)\, indicatin g that this is a more general feature of semiconducting transition metal d ichalcogenides.\n\n$[1]$ J. A. Krieger\, et al.\, arXiv:2206.03051 (2022)\ n\n![(a) Local field distribution in 2H-WSe$_2$ at 5K in a 0.7T transverse field. (b) Applied field dependence of the oscillation frequencies in 2H- MoTe$_2$ at 5.5K.][1]\n\n [1]: https://drive.google.com/uc?id=1NUGb1VbfzO 31TktLqb6v4EWdIl-aieXJ\n\nhttps://indico.stfc.ac.uk/event/53/contributions /3635/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3635/ END:VEVENT BEGIN:VEVENT SUMMARY:Carrier lifetimes in high-lifetime silicon wafers and irradiation induced recombination centres DTSTART;VALUE=DATE-TIME:20220901T132000Z DTEND;VALUE=DATE-TIME:20220901T134000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3637@indico.stfc.ac.uk DESCRIPTION:Speakers: Koji Yokoyama (ISIS\, STFC\, UK)\nPhotoexcited muon spin spectroscopy (photo-$\\mu$SR) was used to measure excess charge carri er lifetimes in passivated silicon wafers. Optically generated excess carr iers interact with muonium centres via carrier exchange interaction and in duce relaxation in the $\\mu$SR time spectrum. The photo-$\\mu$SR techniqu e utilises this additional relaxation rate as a measure of the excess carr ier density\, which in turn enables us to measure carrier lifetime spectra by controlling delays between a muon and laser pulse $[1]$. In addition\, the depth-resolved measurement can characterise carrier kinetics at speci fic depths within a Si wafer and enables us to separate bulk and surface r ecombination rates $[2]$. Based on these developments\, we recently applie d the technique to passivated Si samples with extremely long effective lif etimes ($>$1 ms) and observed that prolonged muon irradiation resulted in significant degradation of a measured lifetime $[3]$. Follow-up characteri sation measurements\, including deep-level transient spectroscopy\, strong ly suggested that beam damage generated defect-related recombination centr es in bulk. Our results demonstrate an extremely rare case in $\\mu$SR app lications\, where beam damage to crystalline lattice was clearly detected by virtue of high-lifetime Si wafers and\, in turn\, low native defect den sities. \n$[1]$ K. Yokoyama\, et al. Phys. Rev. Lett. 119\, 226601 (2017)\ ; Appl. Phys. Lett. 115\, 112101 (2019).\n$[2]$ K. Yokoyama\, et al. Appl. Phys. Lett. 118\, 252105 (2021).\n$[3]$ J. D. Murphy\, et al. submitted t o Journal of Applied Physics.\n\n![A series of repeat lifetime measurement s were performed on a HfO$_2$ passivated Si sample. (a): Effective carrier lifetimes were measured as a function of beam exposure time. (b): A photo luminescence lifetime image was taken on the sample (5$\\times$5 cm$^2$) a fter the muon experiment. White parts closer to the edges indicate longer carrier lifetimes. The central black spot with shorter lifetimes correspon ds to a region exposed to muon beams.][1]\n [1]: https://ucc98303ba1c74bf 870642bd8ca6.previews.dropboxusercontent.com/p/thumb/ABmahQ2Y1qE6orS1BxHIE 1m2IMRHSMAYbvvHU97P-ItKYc4-NMbqPZVl2ucnv0Ac_6butSqCkTtb0wlfrXwga1KEFkenCxZ ZRsPib2mW2CDTjgdlTDLBjr3LDoJ-sM_ye9luB0mIB2z1g-_VwvHee8VxCk9QUiaWaBDlDiJms wRn2OnIng3FeXPUbpqNJNboxrBGDpZNo03clYgnV8KB3JXEndLIgJ_CJ_vKLfCvLhOVOxaLg8A qX64Tkuoyz0AqVoX1TXVcyG_k7GwcGchcg6BnhSOjEELKBsfkbf9H3hufgSqhv8_i0ZuAlvdgs X-aQ3i8BSrc5PbytV-sRl3xKUfFVNSUO8l9RynS_8qZQA58DKUldaeeEb-55-UzJbE2gJvEU9v DnrrdqngaxbaKA2saPdSrDfExQ-ZCky8RWU2x-A/p.jpeg\n\nhttps://indico.stfc.ac.u k/event/53/contributions/3637/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3637/ END:VEVENT BEGIN:VEVENT SUMMARY:Ambipolar Property of Isolated Hydrogen in Oxide Materials Reveale d by Muon DTSTART;VALUE=DATE-TIME:20220901T134000Z DTEND;VALUE=DATE-TIME:20220901T140000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3638@indico.stfc.ac.uk DESCRIPTION:Speakers: Ryosuke Kadono (IMSS\, KEK)\, Masatoshi Hiraishi (IM SS\, KEK)\nThe study on the electronic state of muon as pseudo-hydrogen (r epresented by the elemental symbol Mu) by muon spin rotation has long been appreciated as one of the few methods to experimentally access the electr onic state of dilute hydrogen (H) in semiconductors and dielectrics. Meanw hile\, theoretical predictions on the electronic state of H in these mater ials by first-principles calculations using density functional theory (DFT ) do not always agree with the observed states of Mu. In order to address this long-standing issue\, we have re-examined the vast results of previo us Mu studies in insulating/semiconducting oxides with special attention t o the non-equilibrium character and the ambipolarity of Mu. As a result\, we established a semi-quantitative model that enables systematic understan ding of the electronic states of Mu in most oxides.\nFirst of all\, Mu oft en occurs simultaneously in a neutral (Mu$^0$) and a diamagnetic state (Mu $^+$ or Mu$^-$) in wide-gap oxides\, which is not explained by DFT calcula tions that predict only diamagnetic states with the polarity determined by the equilibrium charge-transition level ($E^{+/-}$). Our model considers that $\\mu^+$ interacts with self-induced excitons upon implantation to fo rm relaxed-excited states corresponding to a donor-like (Mu$_D$) and/or an acceptor-like (Mu$_A$) states. Moreover\, these states are presumed to ac company the electronic level ($E^{+/0}$ or $E^{-/0}$) predicted by the DFT calculations for H. By considering that the stability of these two state s including their valence is determined by i) the relative position of $E^ {\\pm/0}$ in the energy band structure of the host and ii) a potential bar rier associated with the transition between Mu$_D$ and Mu$_A$\, we find th at the known experimental results can be explained systematically in accor dance with $E^{\\pm/0}$. The model also provides new insights into the pol aron-like nature of the electronic states associated with shallow donor Mu complexes and the fast diffusion of Mu$^0_A$.\n\nhttps://indico.stfc.ac.u k/event/53/contributions/3638/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3638/ END:VEVENT BEGIN:VEVENT SUMMARY:Positive muons\, electrons\, and nanostructures DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3719@indico.stfc.ac.uk DESCRIPTION:Speakers: Khashayar Ghandi ()\nIn this presentation\, I will s how where positive muons shine light on nanochemistry uniquely\, where the y provide complementary information to pulse radiolysis and where the muon laser spectroscopy stand in this complementary world of positive muons an d electrons. I will show some of our pulse radiolysis data and our muon sp in spectroscopy data obtained from our work on different nanostructures in the solid state and in liquids.\n\nhttps://indico.stfc.ac.uk/event/53/con tributions/3719/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3719/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of a drift tube for study of a quantum mechanical scat tering of muons in helum gas DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3720@indico.stfc.ac.uk DESCRIPTION:Speakers: Shiro MATOBA (High Energy Accelerator Research Organ ization)\nThe first principle calculation involving muon needs to consider the effect of quantum fluctuations as well and it is still in a state of development. In order to verify the first principle calculation\, the basi c data for the collision cross section at low energy region corresponding to the binding energy of the muon and the target molecule is necessary. Es pecially the elastic scattering cross sections and the potential energy su rfaces in the thermal energy region are extremely important for studying t he muon behavior in the envi-ronment. However\, since the collision experi ment in this energy region is technically difficult\, the report of experi mental results for the interaction between two bodies in an isolated syste m\, especially for the elastic scattering\, is sparse. By applying the dri ft tube technique to the muon collision experiment\, we consider that info rmation of interactions between a muon and a molecule in gas can be obtain ed for less than 1 eV region. \nThe positive muons (~2.7 MeV) generated ar e passed through an thin aluminum plate and to decelerate it to 100 keV. The decelerated muons enter the drift tube and travel a few centimeters by repeatedly colliding with buffer gas (~100 kPa) and then thermalizes. The thermalized muon travels with certain mobility toward the back due to the uniform electric field (~100 V/cm) applied to the inside of the drift tub e. After the muons travel a few centimeters from the point where it therma lized\, they decay to positrons. The positrons pass through the double sci ntillation fiber installed on the outside of the drift tube.By installing the fibers in double\, the flight direction of the positron can be determi ned and the projection diagram to the central axis of the drift tube at th e decay point can be obtained.\nWe have successfully measured the muon sto p position at the S-line.\n\nhttps://indico.stfc.ac.uk/event/53/contributi ons/3720/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3720/ END:VEVENT BEGIN:VEVENT SUMMARY:Universal fluctuating regime in triangular chromate pure Heisenber g S=3/2 antiferromagnets DTSTART;VALUE=DATE-TIME:20220901T074000Z DTEND;VALUE=DATE-TIME:20220901T080000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3640@indico.stfc.ac.uk DESCRIPTION:Speakers: Philippe Mendels (Université Paris(Sacaly)\nThe ser ies of triangular compounds ACrO$_2$ is a model series for studying the He isenberg model on S=3/2 (Cr$^{3+}$: half-filled t$_{2g}$ orbitals) triangu lar antiferromagnets and the impact of interlayer couplings on the dynamic s. For this\, we report µSR measurements on α-HCrO$_2$ and KCrO$_2$ [1] which complete former studies on the series of triangular compounds ACrO$_ 2$\, A = Li \, Na [2\, 3]. Coupled to $^1$H and $^{39}$K nuclear magnetic resonance (NMR)\, we establish the static character at low-T\, as expected for a near neighbour Heisenberg model\, yet displaying a broad and remark able regime with slow fluctuations extending from $T_N$ down to 0.2 $T_N$. This regime is marked by a maximum in the μSR relaxation rate occuring a t 0.7 $T_N$\, associated with an NMR wipe-out .\nThe scaling of the NMR an d μSR data with respect to J or T$_N$ supports a scenario where a crossov er from 2D to 3D correlations sets in around 0.7 T$_N$ preceded by a typic al 2D regime of the TLHAF which appears to be a hallmark of the TLHAF with ABC stacking. We discuss the role of interlayer frustration which may bea r implications to recent spin-liquid candidates with the triangular geomet ry and exclude a scenario à la Berezinskii-Kostelitz-Touless of vortex-an tivortex topological excitations in that regime. In turn\, this underlines the crucial need of further neighbour interactions\, anisotropy typical of rare earth or even disorder to stabilize a quantum spin liquid state in triangular antiferromagnets such as YbMgGaO$_4$.\n[1] K. Somesh et al. Ph ys. Rev. B 104\, 104422 (2021).\n[2] A. Olariu et al. Phys. Rev. Lett. 97\ , 167203 (2006).\n[3] A. Olariu et al. Phys. Rev. B 79\, 224401 (2009).\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3640/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3640/ END:VEVENT BEGIN:VEVENT SUMMARY:Searching for Spin Liquids in Buckled Compounds DTSTART;VALUE=DATE-TIME:20220901T080000Z DTEND;VALUE=DATE-TIME:20220901T082000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3641@indico.stfc.ac.uk DESCRIPTION:Speakers: Sarah Dunsiger (TRIUMF / Simon Fraser University)\nT he phrase ‘quantum spin liquid’ (QSL) refers to a system in which stro ng quantum fluctuations prevent long-range magnetic order from being estab lished\, even at temperatures well below any interaction energy scale. No spontaneous symmetry breaking is involved\, nor a conventional local order parameter. Thus\, it is not described using the Landau theory of phase t ransitions and constitutes a novel phase of matter. These systems exhibit a wealth of exotic phenomena like long-range entanglement and fractional quantum excitations\, which are of fundamental interest but also hold grea t potential for quantum communication and computation. \n\nMagnetic specie s decorating a two dimensional kagome lattice constitute the most heavily studied QSL candidates. Quantum fluctuations are prevalent due to geometri cal magnetic frustration\, low coordination number and quasi low dimension ality. Two particularly well-studied experimental realisations are volbor thite\, where it is believed spatial anisotropy plays an important role an d herbertsmithite ZnCu$_3$(OH)$_6$Cl$_2$. However\, the presence of exces s Cu$^{2+}$ replacing the nonmagnetic Zn$^{2+}$ induces randomness in the magnetic exchange coupling\, complicating explanations of the experimental observations.\n\nOur focus is the investigation of a series of newly synt hesised QSL candidates. The insulating materials YCu$_3$(OH)$_6$O$_x$Cl$_ {3−x}$ (x = 0\, 1/3) display a kapellasite-like structure and no sign of Cu/Y mixing from single crystal x-ray refinements. In the x = 0 compound\ , the kagome lattice is perfect\; in the x = 1/3 compound\, it is slightly buckled. \n In Ba$_4$Ir$_3$O$_{10}$\, Ir$^{4+}$(5d$^5$) ions form Ir$_3$O $_{12}$ trimers of three dimensional face-sharing IrO$_6$ octahedra\, whi ch are vertex-linked\, forming wavelike 2D sheets. However\, it is propo sed that intra-trimer exchange is reduced and the lattice recombines into an array of coupled 1D chains with additional spins. As such\, the compou nd is a candidate Tomonaga-Luttinger liquid (TLL) and presents a novel rou te to exploring quantum liquid behaviour. A muon spin relaxation investig ation of these novel compounds is discussed.\n\nhttps://indico.stfc.ac.uk/ event/53/contributions/3641/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3641/ END:VEVENT BEGIN:VEVENT SUMMARY:Developments of analysis functions for $\\mu$SR time spectra which show intermediate shapes between Gaussian and Lorentzian DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3790@indico.stfc.ac.uk DESCRIPTION:Speakers: Isao Watanabe (RIKEN)\nHow to choose analysis functi ons is a key matter to deduce the information in physics from the muSR res ults. For instance\, local magnetic fields at the muon site in the paramag netic state are well known to be coming from surrounding nuclear dipole mo ments. In this case\, the field distribution at the muon site becomes to b e the Gaussian distribution [1]. This Gaussian distribution typically occu rs when there are independent contributions from many magnetic sources wit h similar amount of contribution. On the other hand\, in case that\, one m agnetic spin\, which is located nearest to the muon\, tends to give a domi nant contribution\, the local field due becomes random and a different fie ld distribution appears at the muon site. For the dilute limit (effectivel y for concentrations less than 3~5 %)\, the field distribution becomes to be Lorentzian [2]. \n In our presentation\, we described the crossover f ield in terms of a convoluted function of Gaussian and Lorentzian. We deri ved the equation of the three-dimensional (3D) convolution in two ways. Th e first derivation uses the convolution integral starting directly in the 3D space. The other derivation starts from that of the one-dimensional (1D ) convolution and make it to be converted to the 3D form. From the latter\ , we showed that the equation can be decomposed to a sum of three known co nvolutions. By applying the Fourier transform to this equation\, we achiev ed the correct relaxation function for the zero-field condition\, which wa s found to be given by a simple analytical equation. In addition\, we trie d to describe the intermediate analysis function under applied magnetic fi elds and under dynamic fluctuations based on the development of the zero-f ield intermediate analysis function. Finally\, we applied our developed an alysis function to some $\\mu$SR results to make sure its validity [3].\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3790/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3790/ END:VEVENT BEGIN:VEVENT SUMMARY:Insights into skymion-hosting materials from implanted muons DTSTART;VALUE=DATE-TIME:20220829T102000Z DTEND;VALUE=DATE-TIME:20220829T104000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3646@indico.stfc.ac.uk DESCRIPTION:Speakers: Tom Lancaster (Durham University)\nLow-dimensional m agnetism continues to be of great theoretical and experimental interest\, as reduced dimensionality supports strong fluctuations that can result in novel states and excitations. One theme in this field is the understanding of magnetism in reduced dimensions using notions from topology. Examples include topological objects such as walls\, vortices and skyrmions\, which can potentially exist in the spin textures of a range of systems. In rece nt years\, the experimental discovery of skyrmions in magnetic materials a nd of their self-organization into a skyrmion lattice\, together with thei r potential for use as high density\, low-energy sensors and magnetic stor age\, has made the investigation of such magnetic topological objects part icularly important$^{1}$. \n\nHere we report insights gained from our muon -spin spectroscopy ($\\mu^{+}$SR) investigations of materials with topolog ical excitations\, including: (i) order and dynamics in GaV$_{4}$S$_{8-y}$ Se$_{y}$\, a system hosting Néel skyrmions in which $\\mu^{+}$SR shows ho w their stability is enhanced through chemical substitution and the applic ation of pressure$^{2}$\; (ii) the skyrmion-hosting multilayer system Ta/[ CoFeB/MgO/Ta]$_{16}$\, where low-energy $\\mu^{+}$SR uniquely reveals chan ges in the magnetic structure with depth into the multilayer stack\; (iii) Cr$_{1/3}$NbS$_{2}$\, which hosts topological soliton excitations\, and w here we show that the magnetism is determined directly by features in the electronic bandstructure$^{3}$. These investigations demonstrate how the c ombination of $\\mu^{+}$SR\, magnetometry and electronic structure calcula tions\, both to determine muon sites and more generally\, can be used to a chieve additional insights into the underlying magnetic behaviour.\n\n$^{1 }$T. Lancaster\, Contemp. Phys. **60**\, 246 (2019). $^{2}$T.J. Hicken *et al*.\, Phys. Rev. Research **2**\, 032001(R) (2020)\; Phys. Rev B **105** \, 134414 (2022). $^{3}$T.J. Hicken *et al*. Phys. Rev. B **105**\, L0604 07 (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3646/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3646/ END:VEVENT BEGIN:VEVENT SUMMARY:Discovery of Hidden Charge-Neutral Muon Centers in Magnetic Materi als: Implications and Applications DTSTART;VALUE=DATE-TIME:20220831T070000Z DTEND;VALUE=DATE-TIME:20220831T072000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3644@indico.stfc.ac.uk DESCRIPTION:Speakers: Martin Dehn (UBC)\nSpin polarized muons are widely k nown as an extremely sensitive local probe of magnetism. Additionally\, po sitively charged muons implanted into semiconductors and insulators often bind an electron to form a charge-neutral muon-electron bound state freque ntly referred to as a muonium center. While studied extensively in non-mag netic semiconductors and insulators as light analogues of corresponding hy drogen centers\, charge-neutral muon states are rarely considered releva nt in magnetic materials. Apart from the singular exception of antiferro magnetic MnF$_2$[1]\, no long-lived charge-neutral centers had been identi fied in magnetically ordered materials up-to-date. \n\nHere\, we present strong evidence that charge-neutral muon centers *do* exist in magnetic c ompounds. Detailed new $\\mu$SR investigations of the antiferromagnets Cr$ _2$O$_3$[2]\, Fe$_2$O$_3$[3] and MnF$_2$\, in conjunction with density-fun ctional-theory calculations\, reveal that charge-neutral muon states are p resent in magnetic materials and can form with different electronic struct ures\, analogous to the variety of muonium centers found in non-magnetic m aterials.\n\n \nCrucially\, we find that in magnetic materials\, charge-ne utral muon states do not display any signatures conventionally associated with muonium centers\, making it difficult to distinguish them from the o ften assumed positive charge state. We demonstrate that the presence of t he additional charge alters the local electronic and magnetic structure\, affecting the $\\mu$SR signal and its relationship with the intrinsic ma gnetic properties. Since the muon is used extensively as a sensitive magne tic probe\, it is imperative to understand under what conditions charge-ne utral states are formed in magnetic materials\, and what impact they have on the observed $\\mu$SR frequencies and damping rates. \n\n\n\n[1] Uemur a *et al.*\, *Hyperfine Interact.* **31** 313(1986)\n\n[2] M.H. Dehn *et a l.*\, *Phys. Rev. X* **10**\, 011036 (2020) \n\n[3] M.H. Dehn\, J.K. Shent on *et al.*\, *Phys. Rev. Lett.* **126**\, 037202 (2021)\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3644/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3644/ END:VEVENT BEGIN:VEVENT SUMMARY:From $\\mu$SR spectra to the magnetic interaction energy parameter s: the MnSi helimagnet as a test case DTSTART;VALUE=DATE-TIME:20220831T072000Z DTEND;VALUE=DATE-TIME:20220831T074000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3645@indico.stfc.ac.uk DESCRIPTION:Speakers: Pierre Dalmas de Reotier (Univ. Grenoble Alpes)\nFor several decades the intermetallic compound MnSi has fascinated the commun ity for different aspects of its physical and magnetic properties. Among t hese properties is the exotic temperature-magnetic field phase diagram. Wh ile this diagram was first established in the 1970s\, the exact nature of one of the phases was only identified in 2009 as a lattice of magnetic sky rmions\, i.e. a topological magnetic texture.\nIn this contribution we pre sent recent developments in the interpretation of the muon response of MnS i in the helimagnetic and conical phases\, respectively observed in zero a nd finite fields. These developments are based on a computation of the asy mmetry spectrum in terms of the incommensurate magnetic structure paramete rs and the muon site and coupling.\n\nIn a first step we show the magnitud e $m$ of the magnetic moment in the helical phase\, the temperature depend ence of which has attracted little attention in the literature\, to decay as $T^2$ from its low temperature value. We interpret this decay as the re sult of spin waves excitations. The slope of $m$ vs $T^2$ determines the t wo dominant energy contributions in the traditional expression used for ma gnetic energy of the system.\n\nIn a second step\, instead of the previous ly mentioned continuous field model\, we consider a microscopic model for the energy\, accounting for the presence of four magnetic Mn sites in the crystal unit cell and the symmetry elements of the P2$_1$3 space group in which MnSi crystallizes. The minimization of the energy is obtained for st ructures that somewhat deviate from the regular helical and conical phases . This result is consistently confirmed by fits to the asymmetry spectra w hich provide a quantitative determination of the microscopic model paramet ers. Directions for future developments are presented.\n\nhttps://indico.s tfc.ac.uk/event/53/contributions/3645/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3645/ END:VEVENT BEGIN:VEVENT SUMMARY:The site and high field $\\beta$NMR properties of $^8$Li$^+$ impl anted into $\\alpha$-Al$_2$O$_3$ DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3796@indico.stfc.ac.uk DESCRIPTION:Speakers: Andrew MacFarlane (Chemistry Department\, The Univer sity of British Columbia)\nWe present high magnetic field $\\beta$NMR meas urements of $^8$Li$^+$ implanted in single crystals of sapphire\, a common ly used backing material for other samples. From the well-resolved quadrup olar splitting\, we extract the electric field gradient (EFG) at the impla nted $^8$Li$^+$ site. Comparison with supercell density functional theory calculations of the EFG allows us to identify the octahedral interstitial site as the most likely candidate. In contrast to the zero field $\\beta$N QR spectra\, only a single site is evident at high field. We discuss possi ble explanations for this discrepancy. The high field spin lattice relaxat ion is extremely slow ($1/T_1 \n\nhttps://indico.stfc.ac.uk/event/53/contr ibutions/3796/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3796/ END:VEVENT BEGIN:VEVENT SUMMARY:Intriguing Topological Kagome Magnetism of TbMn$_6$Sn$_6$ DTSTART;VALUE=DATE-TIME:20220902T094000Z DTEND;VALUE=DATE-TIME:20220902T100000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3648@indico.stfc.ac.uk DESCRIPTION:Speakers: Charles Mielke III (Paul Scherrer Institut)\nMagneti c topological phases of quantum matter are an emerging frontier in physics and material science [1-6]\, of which kagome magnets appear as a highly p romising platform. Here\, we explore magnetic correlations in the recently identified topological kagome system TbMn$_{6}$Sn$_{6}$ using $\\mu$SR\, combined with local field analysis and neutron diffraction [1\,4]. Our stu dies identify an out-of-plane ferrimagnetic structure with slow magnetic f luctuations which exhibit a critical slowing down below T$^{*}_{C1}\\simeq $ 120 K and finally freeze into static patches with ideal out-of-plane ord er below T$_{C1}\\simeq$ 20 K. The appearance of the static patches sets i n at a similar temperature as the appearance of topological transport beha viors. We further show that a hydrostatic pressure of 2.1 GPa stabilizes t he static out-of-plane topological ferrimagnetic ground state in the whole volume of the sample. Therefore the exciting perspective arises of a magn etically-induced topological system whose magnetism can be controlled thro ugh external control parameters. The present results [4] will stimulate th eoretical investigations to obtain a microscopic understanding of the rela tion between the low-temperature volume-wise magnetic evolution of the sta tic $c$-axis ferrimagnetic patches and the topological electronic properti es in TbMn$_{6}$Sn$_{6}$.\n\n[1] J.-X. Yin et al.\, Nature $\\textbf{583}$ \, 533-536 (2020).\n[2] Z. Guguchia et al.\, Nature Comm. $\\textbf{11}$\, 559 (2020).\n[3] N.J. Ghimire and I.I. Mazin\, Nature Materials $\\textbf {19}$\, 137-138 (2020).\n[4] C. Mielke III et al.\, arXiv:2101.05763 (2021 ).\n[5] C. Mielke III et al.\, Phys. Rev. Materials $\\textbf{5}$\, 034803 (2021).\n[6] C. Mielke III et al. … Z. Guguchia\, Nature $\\textbf{602} $\, 245-250 (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/36 48/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3648/ END:VEVENT BEGIN:VEVENT SUMMARY:Towards a microscopic understanding of charge carrier mobility in dielectrics with muon spectroscopy DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3795@indico.stfc.ac.uk DESCRIPTION:Speakers: Ben Orton (STFC)\, Stephen Cottrell (STFC)\nThis pap er reports the development of a novel technique using spin polarised posit ive muons to probe local charge redistributions within polymeric dielectri cs under externally applied E-fields (EEF’s). These materials are used i n many high voltage applications\, and knowledge of charge dynamics is cru cial to their successful use\, as it dictates their ultimate ability to fu nction as a dielectric. Conventional bulk characterisation methods are use ful tools in this regard\, but only give information at a micron level\, w hereas muons give a molecular view and can therefore bring new insight int o how charge transport at this level develops prior to breakdown. Here we report the first investigation of this type\, studying muons implanted in a polymer epoxy (DGEBA) subjected to an EEF.\nDGEBA consists of long chain molecules\, including phenyl groups\, where muonium can add to form radic al states. We have measured ALC lines in this system and found a broad res onance peak with a coupling consistent to addition to the ring. When expos ed to a comparatively large externally applied electric field (EEF)\, but still well below its intrinsic breakdown voltage (Vbr)\, a change in the m uon asymmetry across the entire resonance peak was observed. The largest c hange in amplitude was observed at the magnetic field corresponding to the centre of the ALC resonance. Working at this fixed magnetic field\, chan ges in amplitude of the resonance curve were explored as a function of app lied EEF. Both negative and positive EEF’s were applied along the beam d irection.\nMeasurements show an almost perfect linear dependence of the as ymmetry of the ALC line to the applied EEF. However\,there is a curious de parture in this behaviour when small negative EEF's are applied that merit s further investigation. Our contribution discusses early results and cons iders what they tell us about charge mobility in DGEBA on the microscopic level.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3795/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3795/ END:VEVENT BEGIN:VEVENT SUMMARY:Thin Film and Surface Preparation Chamber for the Low Energy Muons Spectrometer DTSTART;VALUE=DATE-TIME:20220830T162000Z DTEND;VALUE=DATE-TIME:20220830T164000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3721@indico.stfc.ac.uk DESCRIPTION:Speakers: Hanna Teuschl (Laboratory for Muon-Spin Spectroscopy \, Paul Scherrer Institute\, Switzerland)\nWe have designed and constructe d a thin film preparation chamber with base pressure of $\n\nhttps://indic o.stfc.ac.uk/event/53/contributions/3721/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3721/ END:VEVENT BEGIN:VEVENT SUMMARY:Two-component superconductivity in Sr$_2$RuO$_4$ studied by unia xial and hydrostatic pressure $\\mu$SR DTSTART;VALUE=DATE-TIME:20220829T130000Z DTEND;VALUE=DATE-TIME:20220829T132000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3651@indico.stfc.ac.uk DESCRIPTION:Speakers: Hans-Henning Klauss (TU Dresden)\nAfter two decades of research\, the symmetry of the superconducting state in Sr$_2$RuO$_4$ i s still under strong debate. The long time favoured spin-triplet px + i py state is ruled out by recent NMR experiments (1). However\, in general ti me-reversal-symmetry breaking (TRSB) superconductivity indicates complex t wo-component order parameters. Probing Sr$_2$RuO$_4$ under uniaxial pressu re offers the possibility to lift the degeneracy between such components ( 2). One key prediction for Sr$_2$RuO$_4$\, a splitting of the superconduct ing and TRSB transitions under uniaxial pressure has not been observed so far. \nHere\, we report results of muon spin relaxation (μSR) measurement s on Sr$_2$RuO$_4$ placed under uniaxial stress (3). We observed a large p ressure-induced splitting between the onset temperatures of superconductiv ity (T$_c$) and TRSB (T$_{\\mathrm{TRSB}}$). Moreover\, at high stress bey ond the van Hove singularity\, a new spin density wave ordered phase is ob served. \nTo distinguish between a symmetry protected chiral state (d+id) and non-chiral accidentally degenerated order parameters (d+ig\, f+ig) we also report $\\mu$SR studies under symmetry conserving hydrostatic pressur e. In these experiment no splitting between T$_c$ and T$_{\\mathrm{TRSB}}$ is observed (4). \nIn this talk we discuss the implications on the superc onducting order parameter in Sr$_2$RuO$_4$.\n\n![(Left) Electronic phase d iagram of Sr$_2$RuO$_4$ versus uniaxial pressure applied along the direc tion (3). (Right) TRSB transition temperature versus superconducting trans ition temperature of Sr$_2$RuO$_4$ under hydrostatic and uniaxial pressure and La impurity doping (4).][1]\n\n\n*This work was supported by DFG (GR 4667\, GRK 1621\, and SFB 1143).\n(1) A. Pustogow\, et al.\, Nature 574\, 72 (2019)\n(2) C. Hicks\, et al.\, Science 344\, 283 (2014)\, M. E. Barbe r\, et al.\, Phys. Rev. Lett. 120\, 076602 (2018).\n(3) V. Grinenko\, S. G hosh\, et al.\,  Nat. Phys. (2021) \n(4) V. Grinenko\, et al.\, Nat. Co mm. (2021)\n\n\n [1]: https://photos.app.goo.gl/sxZgmtgJDn434g4T7\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3651/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3651/ END:VEVENT BEGIN:VEVENT SUMMARY:$\\mu$SR Study of the Relationship between the Magnetism\, Superco nductivity and Electronic Nematicity in Iron-Chalcogenide Thin Films DTSTART;VALUE=DATE-TIME:20220901T100000Z DTEND;VALUE=DATE-TIME:20220901T102000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3652@indico.stfc.ac.uk DESCRIPTION:Speakers: Tadashi Adachi (Sophia University)\nThe iron-chalcog enide FeSe exhibits various electronic states such as superconductivity\, the so-called electronic nematicity\, as well as a magnetic order under hy drostatic pressure. Therefore\, this system attracts considerable researc h attention in an effort to understand the interplay between the different electronic states. In S-substituted thin films of FeSe$_{1-x}$S$_x$ in w hich positive chemical pressure is induced by the smaller S substitution f or larger Se\, we formerly found a kink in the temperature dependence of t he electrical resistivity at highly S-substituted thin films of $x \\ge 0. 18$ without the nematic state [1]. The kink has been observed around the magnetic transition temperature $T_N$ in bulk FeSe under pressure [2]. To investigate the possible magnetism in FeSe$_{1-x}$S$_x$ and compare with Te-substituted FeSe$_{1-y}$Te$_y$ in which negative chemical pressure is i nduced\, we performed muon-spin-relaxation ($\\mu$SR) measurements [3]. \ nZero-field $\\mu$SR time spectra of FeSe$_{1-x}$S$_x$ with $x=0.3$ and $0 .4$ revealed the formation of a short-range magnetic order at low temperat ures. The value of $T_N$ is higher in $x=0.4$ than in $x=0.3$\, suggestin g a S-induced magnetic order in the FeSe$_{1-x}$S$_x$ thin films. For sli ghtly S-substituted $x=0.1$ with the nematic state\, on the other hand\, i t was found that a long-range magnetic order was formed at low temperature s. As the value of $T_N$ at $x=0.1$ is higher than that of $x=0.4$\, dist inct magnetic states would be formed in the slightly (with nematic) and hi ghly (without nematic) S-substituted FeSe$_{1-x}$S$_x$.\n\n[1] F. Nabeshim a *et al*.\, J. Phys. Soc. Jpn. **87**\, 073704 (2018).\n[2] T. Terashima *et al*.\, J. Phys. Soc. Jpn. **84**\, 063701 (2015).\n[3] F. Nabeshima *e t al*.\, Phys. Rev. B **103**\, 184504 (2021).\n\nhttps://indico.stfc.ac.u k/event/53/contributions/3652/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3652/ END:VEVENT BEGIN:VEVENT SUMMARY:Complex nature of charge order and superconductivity interplay in correlated kagome superconductor CsV$_3$Sb$_5$ DTSTART;VALUE=DATE-TIME:20220901T102000Z DTEND;VALUE=DATE-TIME:20220901T104000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3654@indico.stfc.ac.uk DESCRIPTION:Speakers: Ritu Gupta (Geneva University)\nRecent family of Kag ome superconductors AV3Sb5 (A = Rb\, K\, Cs) offers a natural playground t o study the interplay between different electronic states such as non-triv ial chiral charge order (CO) and unconventional superconductivity [1-5]. T his is because of its unique crystal structure that results in flat bands across the Brillouin zone\, crossing of linear bands at K-corner\, appeara nce of van Hove singularities at M-edges of the Brillouin zone. CsV3Sb5 is of particular interest compared to Rb and K counterparts due to distinct M-dome shaped two peak behaviors in its superconducting transition tempera ture Tc vs. pressure phase diagram. The phase diagram is however drawn thr ough transport measurements accessing only macroscopic nature of interplay between CO and SC [6]. Thus\, microscopic nature and theoretical understa nding of their correlation remains unanswered. We have carried out muon sp in relaxation/rotation (μSR) experiments under hydrostatic pressure up to 1.9 GPa. Nearly threefold enhancement in Tc and superfluid density ns at 1.74 GPa compared to their respective ambient pressure values has been obs erved. Interestingly\, ns also displays two peak like feature with pressur e. Three different regions of phase diagram manifest distinct linear relat ionship between Tc and ns. The μSR results and DFT calculations conjointl y suggest possible evolution of CO from a superimposed tri-hexagonal Star- of-David phase at low pressures to the staggered tri-hexagonal phase at in termediate pressures [7]. Our studies thus uncover different regions of ph ase diagram with CO showing varying degree of interplay with SC. \n\n* contributed equally\n[1] Neupert et al.\, Nature Physics 18\, 137 (2022).\ n[2] Zhao et. al. \, Nature 599\, 216–221 (2021).\n[3] Mielke III et al. \, Nature 602\, 245 (2022).\n[4 Guguchia et al.\, https://arxiv.org/abs/2 202.07713.\n[5] Khasanov et al.\, Phys. Rev. Research 4\, 023244 (2022).\n [6] K. Chen\, et al.\, Physical Review Letters 126\, 247001 (2021).\n[7] R . Gupta et al.\, https://arxiv.org/abs/2203.05055.\n\nhttps://indico.stfc. ac.uk/event/53/contributions/3654/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3654/ END:VEVENT BEGIN:VEVENT SUMMARY:Intense Lyman-alpha light source for ultra-slow muon generation DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3798@indico.stfc.ac.uk DESCRIPTION:Speakers: Yu OISHI (KEK/J-PARC)\nReduction of the momentum wid th in the muon beam is required in particle physics and material science. A small-momentum-width muon beam so called ultra-slow muon beam can be rea lized by laser ionization of muonium which can be produced by stopping of surface muons in a solid target and thermally diffusing them. Such an ultr a-slow muon generation technique reduces the momentum width to about 100 m eV. The application of this ultra-slow muon beam to µSR measurement will enable to measuring of the physical properties from the surface to the int erface of materials more clearly with extremely high depth resolution. In order to efficiently generate ultra-slow muons\, two coherent lights are r equired: the so called Lyman-alpha light\, which resonantly excites muoniu m from the ground state to 2p\, and the 355 nm light\, which ionizes excit ed muonium to the unbound state. In particular\, the generation of intense Lyman-alpha coherent light for resonant excitation is a challenging task in laser technology because the wavelength of the Lyman-alpha light is in vacuum ultraviolet. At J-PARC MLF the Ultra-Slow Muon beamline\, we have successfully generated muonium resonant Lyman-alpha coherent light exceedi ng 10 µJ using an all-solid-state laser and high-efficiency vacuum ultrav iolet light generation technologies\, and we have applied the Lyman-alpha light to the generation of ultra-slow muons. In this presentation\, we wil l describe the current status of our intense Lyman-alpha light source\, an d future upgrade of the light source will be presented.\n\nhttps://indico. stfc.ac.uk/event/53/contributions/3798/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3798/ END:VEVENT BEGIN:VEVENT SUMMARY:Small Sample Measurements at the Low Energy Muon Facility of PSI DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3800@indico.stfc.ac.uk DESCRIPTION:Speakers: Xiaojie Ni (Paul Scherrer Institute)\nThe low energy $\\mu$SR (LE-$\\mu$SR) spectroscopy is primarily used to study thin films \, surfaces\, and interfaces of materials. However\, because of the large beam spot and low implanted muons rate\, LE-$\\mu$SR measurements on small samples are difficult\, requiring an optimal sample area of $ 25\\times25 $ mm$^2$. Recently\, we have boosted our ability to measure small samples\ , down to $5 \\times 5$ mm$^2$ area by beam collimation and tuning. This a dvance is crucial for measurements of many magnetic and superconducting sa mples. Furthermore\, we have devised a method that allows us to measure fi ve small area samples mounted together on the same sample plate. We expect this method to further improve the efficient use of beam at LEM.\n\nhttps ://indico.stfc.ac.uk/event/53/contributions/3800/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3800/ END:VEVENT BEGIN:VEVENT SUMMARY:The Muon Spectroscopy Computational Project DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3801@indico.stfc.ac.uk DESCRIPTION:Speakers: Leandro Liborio (Scientific Computing Department\, R utherford Appleton)\nThis poster presents an overview of the software tool s and techniques that have been developed as part of the Muon Spectroscopy Computational Project (MSCP). The MSCP is an initiative that currently includes: (a) the Muon Group at ISIS\; (b) the Scientific Computing Depar tment\; (c) the UK Software Sustainably Institute and (d) Members of the [ Galaxy][1] platform. The main objective of the MSCP is to support users of muon sources via the development of a sustainable and user-friendly set o f software tools and a software platform that can be used for interpreting muon experiments. \n\nCurrently\, the MSCP has developed and is maintaini ng the following software tools:\n\n• **pymuon-suite**: a Python librar y that can be used to estimate potential stopping sites for the mu+ and th e muonium. \n• **pm-nq**: can be used to estimate the quantum effects o n the muon in accordance with the harmonic approximation. \n• **muspins im**: used for studying the spin dynamics of a system of a muon and other spins. You can simulate LF\, ZF\, TF and ALC experiments. One of the impo rtant features of this tool is that it can be run in parallel and it can a lso be used for fitting experimental results. \n• **Mudirac**: can be used for the prediction of frequencies and probabilities of transition bet ween energy levels of muonic atoms.\n\nThese tools can be easily downloade d and installed and\, as they have been designed in modular way\, they ca n be combined to tackle different problems related to muon science. \n\n \n [1]: https://galaxyproject.eu/\n\nhttps://indico.stfc.ac.uk/event/53/c ontributions/3801/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3801/ END:VEVENT BEGIN:VEVENT SUMMARY:Low Energy Measurements in Low-Energy $\\mu$SR DTSTART;VALUE=DATE-TIME:20220901T152000Z DTEND;VALUE=DATE-TIME:20220901T154000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3655@indico.stfc.ac.uk DESCRIPTION:Speakers: Thomas Prokscha (PSI)\, Zaher Salman (Laboratory for Muon Spin Spectroscopy\, Paul-Scherrer-Institute\, CH-5232 Villigen PSI\, Switzerland)\nIn the context of $\\mu$SR studies on magnetic materials in the ordered state\, often a strong initial depolarization is found in the zero field spectra. For transverse field measurements this is often refer red to as a loss in asymmetry. In case of the low-energy muSR (LE-$\\mu$SR ) setup this needs a more detailed discussion since effects such as time-o f-flight distribution decay\, back scattering\, and muon reflection will c hange the spectra at early times and low implantation energies ($E\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3655/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3655/ END:VEVENT BEGIN:VEVENT SUMMARY:A simulation study of muon transport in the Ultra-Slow Muon beamli ne at J-PARC DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3805@indico.stfc.ac.uk DESCRIPTION:Speakers: N. Teshima (KEK/J-PARC)\nThe Super-Omega beamline at J-PARC Materials and Life Science Experimental Facility provides an inten se pulsed surface muon beam. Combined with a muonium production target and a laser for muonium ionization\, the pulsed ultra-slow muon facility has been developed. At the facility\, a spectrometer for the muon spin rotatio n measurements using the ultra-slow muons is under commissioning. In this poster presentation\, we will report on the beam optics optimization of su rface muon transport and ultra-slow muon extraction to improve the intensi ty and quality of the ultra-slow muon beam.\n\nhttps://indico.stfc.ac.uk/e vent/53/contributions/3805/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3805/ END:VEVENT BEGIN:VEVENT SUMMARY:Role of Many-Body Quantum Effects in μSR Measurements DTSTART;VALUE=DATE-TIME:20220829T084000Z DTEND;VALUE=DATE-TIME:20220829T090000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3658@indico.stfc.ac.uk DESCRIPTION:Speakers: Matjaž Gomilšek (Jožef Stefan Institute\, Jamova c. 39\, SI-1000 Ljubljana\, Slovenia)\nFor unambiguous interpretation of e xperimental µSR data\, a thorough understanding of quantum zero-point mot ion (ZPM) of muons in materials is essential. Namely\, while ZPM of light nuclei like hydrogen and lithium is known to play a pivotal role in the st ructure and dynamics of many important classes of materials$^{1\,2}$\, qua ntum effects of muons in solids can be even stronger due to the lower mass of muons (~1/9 the mass of a proton) and can qualitatively change the mea sured µSR signal$^{3\,4}$.\n\nThere has been much interest in using *ab i nitio* computation of muon stopping sites in materials to aid in the inter pretation of µSR measurements. However\, most computational techniques em ployed have either neglected quantum muon ZPM\, or applied poorly controll ed approximations to it with little clarity around the limits of their app licability. To address this\, we have developed a unified description of l ight-particle ZPM in materials$^{4}$\, clarifying the roles many-body quan tum entanglement and anharmonicity play in determining the true ZPM regime . As proof of concept we applied these insights to our precision µSR quad rupolar level-crossing measurements on solid nitrogen\, α–N$_2$\, where they allowed us to significantly improve the accuracy of the extracted $^ {14}$N nuclear quadrupolar coupling constant. This represents the first im provement in its accuracy in over 45 years\, despite the ubiquity of solid nitrogen in nature\, and a validation of our unified description of light -particle ZPM.\n\n$^{1}$T. E. Markland and M. Ceriotti\, Nat. Rev. Chem. * *2**\, 0109 (2018). $^{2}$E. Snider *et al.*\, Nature **586**\, 373 (2020) . $^{3}$S. J. Blundell\, R. De Renzi\, T. Lancaster and F. L. Pratt\, Muon Spectroscopy: An Introduction (Oxford University Press\, Oxford\, 2021). $^{4}$M. Gomilšek *et al.*\, arXiv:2202.05859.\n\n![Quadrupolar level cro ssing resonance spectra of quantum muons in solid nitrogen.][1]\n\n [1]: http://quantum.ijs.si/wp-content/uploads/2022/07/Time-tracks-plot-2i4-adde d-JEMS-2022-figure-Time-frequency-dependence-Log-scale-For-JEMS-2022-Resiz e-300px-Resave-100.jpg\n\nhttps://indico.stfc.ac.uk/event/53/contributions /3658/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3658/ END:VEVENT BEGIN:VEVENT SUMMARY:Entanglement between muon and I>1/2 nuclear spins as a probe of ch arge environment DTSTART;VALUE=DATE-TIME:20220831T090000Z DTEND;VALUE=DATE-TIME:20220831T092000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3660@indico.stfc.ac.uk DESCRIPTION:Speakers: Pietro Bonfà ()\nQuantum coherence between an impla nted positively-charged muon and nuclei in a solid was first conclusively demonstrated using muon-spin spectroscopy experiments on simple ionic fluo rides [1]. In this case the nuclear spin $I=\\frac 1 2$ of the $^{19}$F nu clei couples to the muon spin through the dipolar interaction.\nHere we id entify the first example of muon spin quantum coherence in systems with nu clear spin larger than $\\frac 1 2$. The effect is shown for vanadium inte rmetallic compounds which adopt the A15 crystal structure\, and whose memb ers include all technologically dominant superconductors.\n\nThe presence of $I\\ge 1$ nearest neighbours (nn) nuclei implies the inclusion of quadr upolar interactions. The muon embedding in the crystal drastically alters the electric field gradient (EFG) at the nuclei nearest neighbours of the muon. Nevertheless\, this perturbation can be effectively described with D ensity Functional Theory based simulations [2]. Once the muon site\, the s tructural distortion and the charge perturbation induced by the muon are e stablished through cost effective *ab initio* simulations\, our modelling of the coherence is extremely accurate.\n\nThis case-study demonstrates th at high-statistics measurements of systems in which the muon spin becomes entangled with nearby nuclear spins can yield information about small chan ges in local structure and charge order\, even in the absence of magnetic ground states.\n\n[1] J. H. Brewer\, et al.\,Phys. Rev. B **33**\, 7813R ( 1986)\n[2] P. Blaha\, et al.\, Phys. Rev. Lett. **54**\, 1192 (1985)\n\nht tps://indico.stfc.ac.uk/event/53/contributions/3660/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3660/ END:VEVENT BEGIN:VEVENT SUMMARY:Status of the New Muonic Helium Atom HFS Measurements at J-PARC MU SE DTSTART;VALUE=DATE-TIME:20220901T150000Z DTEND;VALUE=DATE-TIME:20220901T152000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3659@indico.stfc.ac.uk DESCRIPTION:Speakers: Patrick Strasser (KEK)\nWe recently proposed new pre cision microwave spectroscopy measurements of the ground-state hyperfine s tructure (HFS) of muonic helium atom [1]. Muonic helium is a hydrogen-like atom composed of a helium atom with one of its electrons replaced by a ne gative muon. The ground-state HFS\, resulting from the interaction of the remaining electron and the negative muon magnetic moment\, is very similar to that of muonium but inverted\, and the same technique can be used to p recisely measure muonic helium HFS. It is a sensitive tool to test three-b ody atomic system\, bound-state quantum electrodynamics theory\, and deter mine fundamental constants of the negative muon magnetic moment and mass. The world most intense pulsed negative muon beam at J-PARC MUSE gives an o pportunity to improve previous measurements\, and to test further CPT inva riance through comparison of the magnetic moments and masses of positive a nd negative muons.\nTest measurements at D-line are in progress utilizing MuSEUM apparatus at zero field. Muonic helium HFS were measured at differe nt helium pressures to determine the pressure shift using methane as an el ectron donor. The obtained results have already better accuracy than previ ous measurements [2\,3]. Muonium HFS was also measured to investigate the isotopic effect on the pressure shift.\nWe also started investigating a ne w experimental approach to improve HFS measurements by repolarizing muonic helium atoms using a spin exchange optical pumping (SEOP) technique [4]. If successful\, this would drastically improve the measurement accuracy.\n An overview of the different aspects of these new muonic helium HFS measur ements and the latest results will be presented.\n\n[1] P. Strasser\, et a l.\, JPS Conf. Proc. 21 (2018) 011045.\n[2] H. Orth\, et al.\, Phys. Rev. Lett. 45 (1980) 1483.\n[3] C.J. Gardner\, et al.\, Phys. Rev. Lett. 48 (19 82) 1168.\n[4] A.S. Barton\, et al.\, Phys. Rev. Lett. 70 (1993) 758.\n\nh ttps://indico.stfc.ac.uk/event/53/contributions/3659/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3659/ END:VEVENT BEGIN:VEVENT SUMMARY:Super-MuSR scientific design: Progress towards a step-change in mu on capabilities at ISIS DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3806@indico.stfc.ac.uk DESCRIPTION:Speakers: Peter Baker (STFC)\nSuper-MuSR is a major project to upgrade the MuSR instrument at ISIS that aims to provide an order of magn itude increase in resolution and counting rate in separate modes of operat ion. This now forms an early part of the ISIS-wide Endeavour programme\, a n estimated £90m investment in new and upgraded instruments\, which we ar e aiming to start in the 23/24 financial year.\n \nExperiments using the c urrent MuSR instrument generally focus on magnetism and superconductivity\ , particularly those situations where weak relaxation rates are observed. To extend these capabilities a new detector array will increase the data c ollection rate by more than fifteen times. This will also enable detailed studies of quantum coherent muon states and in-operando diffusion measurem ents of battery cells. The present instrument is limited in the frequency range it can study by the intrinsic muon pulse width at ISIS. This issue w ill be overcome using a pulse slicer to remove both ends of the incoming p ulse and increase the time resolution approximately ten-fold\, albeit redu cing the muon flux. Complementing this will be spin rotators to allow tran sverse field measurements over 0.1T. These will increase the range of magn etic and superconducting samples that can be studied. A new cruciform will permit either fly-past measurements for smaller samples with lower backgr ounds or quick changes between cold dilution fridges for high experiment t hroughput for larger samples as now.\n\nWe have now completed the scientif ic design of the instrument and are now prototyping individual beamline an d spectrometer components. Here we report the progress made with the scien tific design of the beamline and instrument to realise our scientific goal s\, with likely performance evidenced through simulations.\n\n![Planned la yout of the Super-MuSR beamline and spectrometer][1]\n\n\n [1]: https://w ww.isis.stfc.ac.uk/Gallery/Super-MuSR%20Beamline%20overview.png\n\nhttps:/ /indico.stfc.ac.uk/event/53/contributions/3806/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3806/ END:VEVENT BEGIN:VEVENT SUMMARY:Studies of $\\mu^+$ Diffusion and Trapping in dilute Fe Alloys by Longitudinal $\\mu^+$ Spin Relaxation Technique DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3810@indico.stfc.ac.uk DESCRIPTION:Speakers: Nobuhiko Nishida (JAEA & Tokyo Tech.)\nIn the late 1 970s and 1980s $\\mu^+$spin rotation experiments were performed elaboratel y to study $\\mu^+$ diffusion and trapping in Fe and Fe alloys. In Fe allo ys not many experiments were performed\, probably because the unavoidable inhomogeneity of the magnetization in ferromagnetic Fe alloys bring about the fast dephasing of spin rotation and may obscure the diffusion and trap ping effects. Recently at J-PARC MUSE we have found that the measurement o f the longitudinal $\\mu^+$spin relaxation time $T_L$ in ferromagnetic Fe alloys is the effective new microscopic technique to study the $\\mu^+$ di ffusion and trapping in Fe dilute alloys and to investigate how the hydrog en interacts with the principal alloying elements in an attractive or repu lsive manner and how the local lattice strain induced by them affect the h ydrogen diffusion. We revisit the $\\mu^+$SR studies of diffusion and trap ping in Fe alloys. We have measured the temperature dependence of the $T_L $ in several dilute Fe alloys containing principal alloying elements such as Ni\, Mn\, Cr\, Ti\, Al\, Si and interstitial impurities C and O. In so me alloys the temperature dependence of $1/T_L$ exhibits the peaks and in some other alloys a hump in a broad temperature region. We have developed the `two-state' model of ferromagnetic dilute Fe alloys: the trapped stat e by impurity atom and the freely diffusing state of $\\mu^+$. The $\\mu^+ $SR results are well explained by this model. The peaks are due to the mot ional narrowing effect where the $\\mu^+$-impurity interaction is repulsiv e and the $\\mu^+$ diffuse in the crystal apart from the impurity atoms. T he broad hump is due to the trapping and de-trapping of $\\mu^+$ by impuri ties. The 1st principle calculations of hydrogen-impurity interactions\, t he magnetic moment of the impurity and the local strain induced by the imp urity in dilute Fe alloys are compared with the $\\mu^+$SR results.\n\nhtt ps://indico.stfc.ac.uk/event/53/contributions/3810/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3810/ END:VEVENT BEGIN:VEVENT SUMMARY:Developments on muonic X-ray measurement system for historical-cul tural heritage samples in Japan Proton Accelerator Research Complex (J-PAR C) DTSTART;VALUE=DATE-TIME:20220829T144000Z DTEND;VALUE=DATE-TIME:20220829T150000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3663@indico.stfc.ac.uk DESCRIPTION:Speakers: Motonobu Tampo (KEK)\nNegative muon elemental analys is\, which can measure elemental compositional distribution in the depth d irection from 100 nm to several centimeters in a cm-order area with a dept h resolution on the order of μm\, is a revolutionary technology that enab les nondestructive analysis of samples that previously could only be cut a nd analyzed in cross-section.　In recent years\, this technique has begun to be applied to historical cultural heritage\, and has already been carr ied out on Japanese archaeological heritage\, beginning to provide new ins ights into Japanese archaeological research. In this talk\, we will report on the development of a negative muon X-ray measurement system for elemen tal analysis of historical cultural heritage at the KEK Muon Science Labor atory (MSL) in the Japan Proton Accelerator Research Complex (J-PARC). At MSL\, machine time is very limited and fast measurement of archaeological samples is required. Therefore\, we are developing a system to measure neg ative muon X-rays from archaeological samples at high speed. For this purp ose\, it is essential to improve the detection efficiency of the detector. Since the analysis of negative muon X-rays requires obtaining energy spec tra over a wide energy range with high resolution\, high-purity germanium semiconductor detectors (HP Ge) are used\; for the pulsed muon source at J -PARC\, the Ge detector can detect only one photon or less per pulse. Henc e\, the use of multiple Ge detectors is essential to obtain high detection efficiency. In addition\, to obtain a high signal-to-noise ratio (S/N)\, noise sources must be identified and suppressed. By increasing the number of detectors and suppressing noise sources\, we have succeeded in increasi ng detection efficiency by about 10 times compared to conventional systems .\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3663/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3663/ END:VEVENT BEGIN:VEVENT SUMMARY:Muon-Induced X-ray Emission (MIXE) at PSI DTSTART;VALUE=DATE-TIME:20220829T150000Z DTEND;VALUE=DATE-TIME:20220829T152000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3664@indico.stfc.ac.uk DESCRIPTION:Speakers: Sayani Biswas (PSI)\nThe Muon-Induced X-ray Emission (MIXE) technique\, first developed in the 1980's mostly for studying fund amental science\, has recently seen a wide usage in the field of applied s ciences\, which includes archaeology\, battery research\, meteorites\, anc ient paintings etc.\nProbing deep inside the material (up to a few mm) and being non-destructive\, this technique is sensitive to all the elements o f the periodic table\, except hydrogen.\nThe continuous muon source at Pau l Scherrer Institute (PSI) along with the newly in-house made instrument i s one of the most powerful setups for an efficient usage of this technique .\nWe present here recent developments of this dedicated detector setup fo r MIXE at PSI\, used at the $\\pi$E1 beamline\, which can deliver negative muon rates between $\\sim$1.5 kHz and $\\sim$100 kHz for a momentum range between 20 MeV/c and 45 MeV/c\, respectively.\nThis setup presently consi sts of 11 HPGe detectors\, with an overall absolute efficiency of $\\sim$5 \\% and a resolution of $\\sim$1 keV (FWHM) for muonic X-ray energies at $ \\sim$100~keV. \nIn addition to the HPGe detectors\, there are two scintil lator detectors\, utilized to detect the muon entrance time and as veto co unter.\nBy making use of the continuous-wave character of the PSI beam\, a clear distinction between X-rays\, produced during the muon cascade\, and $\\gamma$-rays produced after the capture of the muon by the nucleus\, is possible hence providing a second route for the elemental and isotopic de termination.\nThis setup enables the determination of the quantitative ele mental composition within $\\sim$1 h of DAQ time.\nA proof-of-principle ex periment\, using a simple three-layered sandwich sample has been recently published [1]. \nSeveral other experiments on precious objects from archae ology and meteorites along with operando battery samples have been perform ed and the analysis is in progress.\n\n[1] S. Biswas\, L. Gerchow et al.\, App. Sci. 2022\, 12(5)\, 2541.\n\nhttps://indico.stfc.ac.uk/event/53/cont ributions/3664/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3664/ END:VEVENT BEGIN:VEVENT SUMMARY:Introduction to muon spin spectroscopy DTSTART;VALUE=DATE-TIME:20220828T073500Z DTEND;VALUE=DATE-TIME:20220828T080000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3665@indico.stfc.ac.uk DESCRIPTION:Speakers: Francis Pratt (STFC)\nhttps://indico.stfc.ac.uk/even t/53/contributions/3665/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3665/ END:VEVENT BEGIN:VEVENT SUMMARY:Computational techniques to support muon science DTSTART;VALUE=DATE-TIME:20220828T080000Z DTEND;VALUE=DATE-TIME:20220828T082500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3666@indico.stfc.ac.uk DESCRIPTION:Speakers: Leandro Liborio (Scientific Computing Department\, R utherford Appleton)\nhttps://indico.stfc.ac.uk/event/53/contributions/3666 / LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3666/ END:VEVENT BEGIN:VEVENT SUMMARY:Instrumentation for muon spectroscopy DTSTART;VALUE=DATE-TIME:20220828T082500Z DTEND;VALUE=DATE-TIME:20220828T085000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3667@indico.stfc.ac.uk DESCRIPTION:Speakers: Thomas Prokscha (PSI)\nhttps://indico.stfc.ac.uk/eve nt/53/contributions/3667/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3667/ END:VEVENT BEGIN:VEVENT SUMMARY:Structure of muoniated trimethylsilylvinyl radicals DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3718@indico.stfc.ac.uk DESCRIPTION:Speakers: Iain McKenzie (TRIUMF)\nMuoniated vinyl radicals can be produced by Mu addition to triple bonds. Rhodes et al. observed a muon iated radical formed by Mu addition to trimethylsilylacetylene but were un able to determine the structure.1 We have performed additional transverse field muon spin rotation measurements on trimethylsilylacetylene at 298 K and observed that two muoniated radicals were formed\; a major product wit h muon hyperfine coupling constant (*A*μ) of 587.3(1) MHz and a minor pro duct with *A*μ of 570.9(5) MHz. DFT calculations show that Mu addition is preferred to the unsaturated carbon bonded to H and that the resulting ra dical has a non-linear radical centre. Calculated muon hyperfine coupling constants were used to assign the observed radicals\, which are the cis an d trans isotopomers with respect to the trimethylsilyl substituent\, respe ctively.\n1.C.J. Rhodes et al. *J. Chem. Soc.\, Chem. Commun.* **1987**\, 447\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3718/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3718/ END:VEVENT BEGIN:VEVENT SUMMARY:Impact of Growth Conditions on the CH$_3$NH$_3$PbI$_3$ Perovskite Solar Cells\, Studied by Low-Energy $\\mu$SR DTSTART;VALUE=DATE-TIME:20220901T142000Z DTEND;VALUE=DATE-TIME:20220901T144000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3671@indico.stfc.ac.uk DESCRIPTION:Speakers: Xiaojie Ni (Paul Scherrer Institute)\nMetal halide p erovskites (MHPs) have attracted great attention in recent years due to th eir enormous potential for application in optoelectronic devices. However\ , the defects at surface/interfaces and grain boundaries of perovskite fil ms\, which impede the further enhancement of power conversion efficiency ( PCE) and long-term stability of halide perovskite solar cells (PSCs)\, sti ll need to be fully understood. Here\, we studied the impact of different growth conditions on the interface and grain boundaries of CH$_3$NH$_3$PbI $_3$ perovskite films by low-energy $\\mu$SR. Our measurements show that l ow-energy $\\mu$SR can become a powerful technique for studying the defect engineering of PSCs.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/ 3671/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3671/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muon spin relaxation in water and ice DTSTART;VALUE=DATE-TIME:20220828T100000Z DTEND;VALUE=DATE-TIME:20220828T101500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3670@indico.stfc.ac.uk DESCRIPTION:Speakers: Yoko Kimura (Dept. Phys. Osaka Univ.)\nMuons are the main component of cosmic ray particles on the earth\, and most of the cos mic ray muons are injected into water or ice\, which occupy more than 70% of the earth's surface. When negative muons ($\\mu$$^-$) stop in H$_2$O\, they are mainly trapped by oxygen nuclei and form muonic oxygen atoms O$\\ mu$$^-$\, and about 15% of O$\\mu$$^-$ atoms finally change to stable nitr ogen isotopes $^{14}$N or $^{15}$N via the neutron emission after the muon capture process. The nitrogen isotopes produced by such a process may be chemically active due to their high recoil energy and may form various nit rogen compounds through reactions with water molecules. In this situation\ , $\\mu^-$SR spectroscopy is suitable for studying the behavior of such ac tive nitrogen in H$_2$O\, since O$\\mu^-$ atoms also act chemically as nit rogen. In the present study\, we measured $\\mu^-$SR spectra in water and ice to approach what kind of nitrogen compounds are formed by cosmic-ray n egative muons\, and how they affect the surrounding chemical environment.\ n Experiments were carried out at the D1 beamline in the Materials and Lif e Science Experimental Facility (MLF) of J-PARC. H$_2$O and D$_2$O samples were irradiated with a negative muon beam (47 MeV/c\, double pulse)\, and ZF and LF-$\\mu$$^-$SR spectra were measured. The result shows that the r elaxation due to the nuclear dipolar field is observed in solid H$_2$O and D$_2$O at 200 K. The field distribution widths were deduced to be $\\Delt a_H$=0.27 $\\mu$$s^{-1}$ and $\\Delta_D$=0.066 $\\mu$$s^{-1}$\, for H$_2$O and D$_2$O respectively. The relationship between these two values is wel l explained by the difference in the spins and magnetic moments of proton and deuteron.\n In this conference\, we will discuss possible chemical sta tes based on the present results.\n\nhttps://indico.stfc.ac.uk/event/53/co ntributions/3670/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3670/ END:VEVENT BEGIN:VEVENT SUMMARY:Inducing Quantum Criticality in CrCl$_3$ Under Pressure DTSTART;VALUE=DATE-TIME:20220828T120000Z DTEND;VALUE=DATE-TIME:20220828T121500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3673@indico.stfc.ac.uk DESCRIPTION:Speakers: Yuqing Ge (Department of Physics\, Chalmers Universi ty of Technology\, SE-41296 Göteborg\, Sweden)\nAccelerated by the discov ery of graphene\, research on two-dimensional (2D) materials have attracte d tremendous attention both from fundamental and applied sciences. Among t he large number of 2D materials\, chromium trihalides CrX3 (X = Cl\, Br\, I) van der Waals (vdW) magnets have also raised a large interest due to th e existence of many magnetic subtleties that cannot be explained by their magnetic and/or structural transitions. \nNumerous studies were performed on CrI3\, but only a few have been reported so far on its analogue CrCl3. The 2D vdW CrCl3 compound is stabilized under a rhombohedral symmetry\, co nsisting of 2D Cr layers arranged in a honeycomb web fashion and surrounde d by octahedrally coordinated Cl\, with weak vdW inter-layers coupling. Th e layer structure and inter-layer coupling make CrCl3 an ideal system to s tudy under external stimuli such as pressure or magnetic field\, where new intriguing states of matter can be unveiled. With such expectations\, stu dies of CrCl3 under room temperature\, high pressure have been reported[1] . However\, its spin dynamics at low-temperature and high-pressure regime remain unexplored.\nIn this study\, we present the results of our recent m uon spin rotation (MuSR) investigations performed on hydrostatically press ured CrCl3. Our previous MuSR results at ambient pressure revealed success ive transitions from paramagnetic to short-ranged-order-ferromagnetic then to antiferromagnetic states with strong spin dynamics as the temperature decreases[2]. When applying pressure\, we observed that the magnetic groun d state is gradually suppressed. A linear extrapolation points toward the suppression of magnetism at about $p_c$= 30 kbar indicating the possible e xistence of a quantum critical point at $p_c$.[3]\n\n[1] Ahmad\, Azkar Sae ed\, et al. "Pressure-driven switching of magnetism in layered CrCl3." Nan oscale 12.45 (2020): 22935-22944.\n[2] Forslund\, Ola Kenji\, et al. "Spin dynamics in the Van der Waals magnet CrCl3." arXiv preprint arXiv:2111.06 246 (2021).\n[3] Ge\, Yuqing\, et al.\, in preparation.\n\nhttps://indico. stfc.ac.uk/event/53/contributions/3673/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3673/ END:VEVENT BEGIN:VEVENT SUMMARY:Muon-spin relaxation investigation of magnetic bistability in a mo lecule-based material DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3746@indico.stfc.ac.uk DESCRIPTION:Speakers: Alberto Hernandez-Melian (Durham University)\nWe pre sent the results of a muon-spin relaxation ($\\mu^{+}$SR) investigation of the crystalline organic radical compound 4-(2-benzimidazolyl)-1\,2\,3\,5- dithiadiazolyl (HbimDTDA)\, in which we demonstrate the hysteretic magneti c switching of the system that takes place at $T = (249 \\pm 13)\\\,\\math rm{K}$ caused by a structural phase transition. Muon-site analysis using e lectronic structure calculations suggests a range of candidate muon stoppi ng sites. The sites are\nnumerous and similar in energy\, but\, significan tly\, differ between the two structural phases of the material. Despite th e difference in the sites\, the muon remains a faithful probe of the trans ition\, revealing a dynamically-fluctuating magnetically disordered state in the low-temperature structural phase\, which was previously believed to be diamagnetic. This is evidenced by relaxation following the Redfield fo rmula in longitudinal field (LF) measurements\, which is observed\nonly in the low temperature phase. In contrast\, in the high temperature phase th e relaxation is caused by static nuclear moments\, with rapid electronic d ynamics being motionally narrowed from the muon spectra.\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3746/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3746/ END:VEVENT BEGIN:VEVENT SUMMARY:Data analysis for µSR experiments with negative muons. DTSTART;VALUE=DATE-TIME:20220828T123000Z DTEND;VALUE=DATE-TIME:20220828T124500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3675@indico.stfc.ac.uk DESCRIPTION:Speakers: George Gill (University of Oxford / ISIS)\nNegative muons are often overlooked compared to their positive counterpart\, partly due to the loss of around $\\frac{5}{6}$ of the $\\mu^{-}$ spin polarisa tion when a $\\mu^{-}$ cascades down to the 1s muonic ground state after b eing captured by a nucleus. One needs to count for around 36 times as long to get statistics comparable to that of a $\\mu^{+}$SR experiment. Howeve r\, there has been a recent revival of $\\mu^{-}$SR experiments\, particul arly in the study of hydrogen storage and battery materials [1\,2]. When s topped in a material of atomic number $Z$\, $\\mu^{-}$ forms a muonic ato m and cascades down to its ground state. The muon Bohr radius is 200 times smaller than the electron Bohr radius\, and so this probe behaves like an ultra-dilute atom of apparent nuclear charge $Z-1$. The $\\mu^{-}$ will b e strongly hyperfine coupled to the nuclear spin of the capture atom\, but if that nuclear spin is zero\, such as an oxygen in MnO\, the only coupli ng will be to the nuclear dipolar fields in a region very close to that ca pture nucleus. Because of these difficulties new analysis techniques have been developed in WiMDA [3] for the fitting of $\\mu^{-}$SR data\, and we have adapted the DFT+$\\mu^{+}$ technique for the case of a negative muon. Both of these new techniques have been applied to MnO where the dipole fi eld simulations show a large field at the oxygen site\, and DFT+$\\mu^{-}$ calculations show a Jahn-Teller-like distortion around the negative muon. \n\nReferences\n[1] J.Sugiyama *et al* Phys. Rev. Lett. 121\, 087202 (2018 ).\n[2] J. Sugiyama *et al*\, Phys. Rev. Res. 2\, 033161 (2020).\n[3] F.L. Pratt\, Physica B 289-290\, 710 (2000)\n\nhttps://indico.stfc.ac.uk/event /53/contributions/3675/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3675/ END:VEVENT BEGIN:VEVENT SUMMARY:Anomalous behaviour of the mixed phase of superconducting LaFeAsO$ _{1-x}$F$_{x}$ DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3780@indico.stfc.ac.uk DESCRIPTION:Speakers: Giacomo Prando (Dipartimento di Fisica\, Università degli Studi di Pavia\, Italia)\nThe Fe-based superconductors have been ex tensively investigated in view of the intimate interplay of the magnetic a nd superconducting phases developing therein. Here\, we show an anomalous behaviour of the mixed phase in the family of superconducting compounds La FeAsO$_{1-x}$F$_{x}$ as detected by transverse-field muon spin rotation. T his technique is the best tool to probe both the flux line lattice distrib ution and any additional source of magnetism through both the muon depolar ization rate and the local magnetic field at the muon site $B_{\\mu}$. Alt hough the typical shielding behaviour is expected to saturate to a constan t value well below the superconducting transition $T_{c}$\, our results fo r LaFeAsO$_{1-x}$F$_{x}$ show that $B_{\\mu}$ is enhanced in the low-tempe rature regime (see figure). We discuss an extensive investigation of this phenomenon as a function of F doping\, external magnetic field and tempera ture alongside different interpretations for the observed phenomenology\, including a spontaneous magnetic re-entrance and a possible change of the flux line lattice distribution [1].\n\n![Temperature dependence of the int ernal magnetic field at the muon site for LaFeAsO$_{1-x}$F$_{x}$ ($x = 0.1 $) field cooled in a transverse external field $B_{ext} \\simeq 600$ G. An anomalous enhancement is observed in the low temperature regime.][2]\n\n[ 1] Manuscript in preparation (2022).\n\n[2]: http://nmrphysics.unipv.it/wp -content/uploads/2022/07/SFDensity.jpg\n\nhttps://indico.stfc.ac.uk/event/ 53/contributions/3780/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3780/ END:VEVENT BEGIN:VEVENT SUMMARY:Anomalous electrical transport in frustrated intermetallic RCuAs$_ 2$ : the role of spin DTSTART;VALUE=DATE-TIME:20220828T140000Z DTEND;VALUE=DATE-TIME:20220828T141500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3679@indico.stfc.ac.uk DESCRIPTION:Speakers: Mae Abedi (Department of Physics\, Simon Fraser Univ ersity)\nThe Kondo effect was a longstanding theoretical puzzle\, describi ng the scattering of conduction electrons in a metal due to dilute\, local ised d- or f -electron magnetic impurities and resulting in a characterist ic minimum in electrical resistivity with temperature. Extended to a latt ice of magnetic impurities\, the Kondo effect likely explains the formatio n of so called heavy Fermion systems and Kondo insulators in intermetallic compounds\, especially those involving rare earth elements like Ce\, Pr a nd Yb. The hybrisation of the 4f electron states with the conduction band and resultant screening of local moments\, required for Fermi liquid beha vior in the Kondo lattice\, competes with interactions between localised m oments. The diversity in the low temperature properties of heavy Fermion metals\, as well as their highly tunable nature (with magnetic field\, pre ssure\, chemical substitution)\, make these systems invaluable in the inve stigation of the emergent properties of highly correlated quantum material s.\n\nCounterintuitively\, in a class of ternary intermetallic compounds o f the type RCuAs$_2$ (R = rare earth) [1]\, the rare earths like Sm\, Gd\, Tb\, and Dy with strictly localised 4f character\, where the Kondo effect is not anticipated\, also exhibit a pronounced minimum in resistivity wel l above their respective magnetic ordering temperatures. Even more surpri singly\, no such minimum is observed for Pr\, Nd\, and even Yb based membe rs of this series. Recent theoretical predictions suggest geometric magn etic frustration plays a role [2]. More generally\, frustration is though t to be an important additional tuning parameter in the Kondo lattice mode l. A muon spin relaxation investigation of these materials is discussed\, shedding light on the role of magnetic fluctuations in determining the el ectronic transport in heavy Fermion materials.\n\n[1] E.V. Sampathkumaran et al\, Physical Review Letters 91\, 036603 (2003)\; \n[2] Zhentao Wang et al\, Physical Review Letters 117\, 206601 (2016)\n\nhttps://indico.stfc.a c.uk/event/53/contributions/3679/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3679/ END:VEVENT BEGIN:VEVENT SUMMARY:Elemental Depth Profiling using Negative Muon Implantation and X-r ay Tomography of a Copper based Bust representing: the Head of Crying Child. DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3817@indico.stfc.ac.uk DESCRIPTION:Speakers: Adrian Hillier (STFC)\nCopper based busts in the sha pe of heads or shoulder high length\, are known from the Renaissance\, e. g. the small statuettes of the Virgin and Christ\, with heights under 15cm by François Duquesnoy [1] to busts of heights over half a meter [2]. The bust presented in this paper has no comparison to Renaissance statuettes. The contorted face of the Bust\, height about 22cm\, reminds one of the C haracter Heads of Franz Xavier Messerschmidt (1736–1783) [3]. The bust of a crying child has been investigated using negative muons. Negative muo ns are implanted at a known depth and during the capturing process X-rays are emitted\, characteristic of the capturing atom. This statuette compris es of ~CuZn24. At higher momentum implantation the composition of the inne r core of the statuette comprises of calcium sulphate. The material depth profile as obtained from negative muon experiment has been compared with t he X-ray tomography on the bust of the crying child.\nSince the bust is op en on the bottom\, we were able to check the core body and confirm calcium sulphate as core material and confirms our results. One also observes a small iron object in the middle of the core material which was identified by X-ray tomography as a nail.\n\nThe zinc content of the studied bust\, 2 4%\, is much higher than one normally finds in Renaissance bronzes and bra sses and indicates a later manufacture date. The results show that the me thod can be used for ‘closed’ statuettes: providing information on the core material and alloy composition in a non-destructive way.\n[1] Franç ois du Quesnoy. Marion Boudon-Machuel. (2005) Paris.\n[2] The culture of B ronze (2019). Peta Motture. ISBN978-1851779659.\n[3] Die Fantastischen Kö pfe des Franz Xavier Messerschmidt (2007). Hirmer Verlag.\n ISBN978-43 36533777.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3817/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3817/ END:VEVENT BEGIN:VEVENT SUMMARY:Time-reversal symmetry breaking in nonsymmorphic type-I supercondu ctor YbSb$_2$ DTSTART;VALUE=DATE-TIME:20220828T134500Z DTEND;VALUE=DATE-TIME:20220828T140000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3678@indico.stfc.ac.uk DESCRIPTION:Speakers: Anshu Kataria (PhD Scholar)\nThe interplay of superc onductivity with nontrivial topological phases exhibit the fascinating top ological superconductivity\, which has attracted widespan attention from o bserving quasiparticle like Majorana fermions to its application in fault- tolerant quantum computation$^{1\,2}$. It is proposed that the topological superconductivity can be realized in compounds having topological surface states and superconductivity$^3$. Only a few superconducting materials wi th nontrivial topological states have been discovered\, and their supercon ducting ground state/pairing mechanism can not be adequately understood. T herefore\, searching and studying the superconducting ground state of mate rials having nontrivial topological states is vital.\nHere\, we present th e evidence of time-reversal symmetry breaking (TRSB) in the nonsymmorphic type-I superconductor YbSb$_2$\, having a distorted Sb square net crystal structure similar to the other topological system ZrSiS$^{4\,5}$. The micr oscopic muon spin relaxation and rotation investigation confirm the fully gapped type-I superconductivity with broken time-reversal symmetry in its superconducting ground state. This indicates that the nonsymmorphic RSb$_2 $ superconductors are an interesting class of materials that exhibit uncon ventional superconductivity with fascinating properties and warrant great potential for future studies.\n\nReferences:\n1. X. L. Qi et al.\, Rev. Mo d. Phys. 83\, 1057 (2011).\n2. M. Sato et al.\, Rep. Prog. Phys. 80\, 07 6501 (2017).\n3. L. Fu et al.\, Phys. Rev. Lett. 100\, 096407 (2008).\n4. R. Wang et al.\, Inorg. Chem. 5\, 1468 (1966).\n5. S. Klemenz et al.\, Ann . Rev. Mat. Res. 49\, 185 (2019).\n\nhttps://indico.stfc.ac.uk/event/53/co ntributions/3678/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3678/ END:VEVENT BEGIN:VEVENT SUMMARY:Unsupervised machine learning of muons experiments – why? DTSTART;VALUE=DATE-TIME:20220829T120000Z DTEND;VALUE=DATE-TIME:20220829T124000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3699@indico.stfc.ac.uk DESCRIPTION:Speakers: Jorge Quintanilla (University of Kent)\nZero-field m uon spin relaxation experiments probe directly the intrinsic magnetic fiel ds that arise spontaneously in a given material. The full understanding of such experiments requires a microscopic description of the material under investigation\, including its electronic state and the complex interactio ns between the muon and the material’s electronic and structural degrees of freedom. However\, paradoxically\, such experiments can also yield cru cial information about poorly-understood systems\, well before we know eno ugh about them for such detailed modelling. In this talk I will ask two qu estions: “How is this possible?” and “Can we do it better?” To add ress the first question I will review the particular cases of LaNiC$_2$ an d LaNiGa$_2$\, two closely related superconductors where the case for an e xotic\, time-reversal symmetry breaking pairing state is now well establis hed\, with muons experiments having played the key role. I will describe h ow we got to this point\, emphasising the prudent use of phenomenological fitting functions and group-theoretical analyses. I will argue that while such approach cannot substitute detailed microscopic modelling (which has to have the final word) it can be crucial to get us to the point where the latter becomes feasible. I will then address the second question\, specif ically asking whether there is room for improvement in the way we tackle m uons data phenomenologically. I will introduce the concept of unsupervised machine learning\, using Principal Component Analysis and Auto-encoders a s paradigmatic examples. I will propose that unsupervised machine learning can be used to find compact descriptions of muons data\, helping with det ection of phase transitions and material classification\, without requirin g either a microscopic theory or phenomenological fitting functions. I wil l illustrate this with muons data on real magnetic and superconducting mat erials and introduce simple software tools that can be used to carry out s imilar analyses.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3699/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3699/ END:VEVENT BEGIN:VEVENT SUMMARY:Opportunities and challenges of molecular spins in quantum nanosci ence DTSTART;VALUE=DATE-TIME:20220830T070000Z DTEND;VALUE=DATE-TIME:20220830T074000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3700@indico.stfc.ac.uk DESCRIPTION:Speakers: Roberta Sessoli ()\nImplementation of advanced Quant um Technologies might benefit from the remarkable quantum properties shown by molecular spin systems based on the coordination bond. The versatility of the molecular approach combined with rational design has recently boos ted the operativity temperature of molecules acting as bits of memory\, ot herwise known as Single-Molecule Magnets\, or the coherence time of molecu lar spin qubits. The richness and tunability of the spectrum of spin level s make them particularly suitable for quantum error correction\, while spi n-spin interaction can be tuned to realize quantum gates and quantum simul ators. Molecules can also be processed to be deposited on surfaces\, allow ing the realization of hybrid nanostructures. However\, achieving the cont rol of single molecules is also challenging\, requiring to couple the elec tric field\, which can be confined at the molecular scale\, with the spin degrees of freedom of the molecule. Investigation of the spin dynamics at the level of the monolayer requires developing innovative tools and muon s pin resonance might be an important resource. \n\n![][1]\n\n\n [1]: https ://indico.stfc.ac.uk/event/53/images/128-Abstract-Sessoli-Pic1.jpg\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3700/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3700/ END:VEVENT BEGIN:VEVENT SUMMARY:Spin dynamics of V-based molecular magnets with integer spin value s DTSTART;VALUE=DATE-TIME:20220830T074000Z DTEND;VALUE=DATE-TIME:20220830T080000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3681@indico.stfc.ac.uk DESCRIPTION:Speakers: Alessandro Lascialfari (Department of Physics\, Univ ersità degli studi di Pavia\, INFN and INSTM\, Pavia\, Italy)\nIn the pre sent work\, we investigate the spin dynamics of one-dimensional spin-integ er molecular nanomagnets ((CH$_3$)$_2$NH$_2$)V$_7$MF$_8$(O$_2$CtBu)$_ {162 }$C$_7$H$_8$\, with M=Ni/Mn\, in short V$_7$M [1\,2\,3]\, by means of magn etization\, susceptibility and MuSR measurements. These heterometallic nan omagnets contain seven vanadium ions (s=1) and one Ni$^{2+}$ (s=1) or Mn$^ {2+}$ (s=5/2) ion\, arranged in the form of regular rings. The theoretical studies of rings with a finite number of integer spins indicate a gapped ground state and a significant deviation from the Landé rule\, valid for semi-integer spins [4\,5]. On the other hand\, the infinite spin-integer c hain exhibits a topological Haldane gap between the ground state and the f irst excited state [6]. As confirmed by experimental data\, the ground sta te of V$_7$Ni and V$_7$Mn is expected to be antiferromagnetic\, similarly to the molecular nanomagnet V$_7$Zn [1\,2\,7]\, and the exchange coupling constants among the nearest neighbour magnetic ions are estimated to be of the order of a few Kelvin degrees. Susceptibility and magnetization measu rements at low temperatures display anisotropy effects when an external ma gnetic field is applied. The muon longitudinal relaxation rate $\\lambda$ vs temperature\, at magnetic fields $\\mu_0 H \\geq$ 500 G\, in the range $1.5\\leq T\\leq 100 K$\, follows a heuristic Bloembergen-Purcell-Pound mo del [8]. No effect related to a topological gap is evinced.\n\nReferences\ n[1] F. Adelnia\, PhD thesis in Physics\, Università degli studi di Pavia (2016).\n[2] F. Adelnia et al.\, Applied Magnetic Resonance 51\, 1277 (20 20).\n[3] I. Villa\, BD thesis in Physics\, Università degli studi di Mil ano (2018).\n[4] J. Schnack et al.\, Phys. Rev. B 63\, 014418 (2020).\n[5] D. Gatteschi et al.\, Oxford University Press (2011).\n[6] F. Haldane\, P hys. Letters A 93\, 464 (1983).\n[7] F. A. Rusnati\, MD thesis in Physics\ , Università degli studi di Milano (2017).\n[8] N. Bloembergen et al.\, P hys. Rev. 73\, 679 (1948).\n\nhttps://indico.stfc.ac.uk/event/53/contribut ions/3681/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3681/ END:VEVENT BEGIN:VEVENT SUMMARY:What can we learn from muon-stopping site analysis? DTSTART;VALUE=DATE-TIME:20220831T092000Z DTEND;VALUE=DATE-TIME:20220831T094000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3682@indico.stfc.ac.uk DESCRIPTION:Speakers: Benjamin Huddart (Durham University)\nTwo of the mos t fundamental limitations of the muon-spin spectroscopy ($\\mu^+$SR) techn ique are the lack of knowledge of the muon stopping site\, and the uncerta inty surrounding the degree to which the muon distorts its local environme nt. Over the past decade there has been significant progress in calculatin g muon stopping sites using *ab initio* methods\, particularly density fun ctional theory (DFT). These methods can provide significant insight into h ow the muon probes the system\, thereby enhancing the information that can be extracted from a $\\mu^+$SR experiment.\n\nEstablishing the degree to which the muon perturbs it environment can be crucial for confirming that the phenomena observed by the muon are intrinsic to the system under study . Here we investigate the muon stopping states in a range of correlated el ectron systems. 1) In superconductors that exhibit time-reversal symmetry breaking\, where spontaneous magnetic fields have been observed using $\\m u^+$SR\, we show how knowledge of the muon stopping site shows how the muo n is a faithful probe that provides sensitivity to the intrinsic magnetism in the system [1]. 2) By calculating the muon site and its associated hyp erfine interactions in the quantum spin-liquid candidate 1T-TaS$_2$ we can model how the muon couples to diffusing spinon excitations [2]. Here we a re also able to compute details of the muon's own diffusion between sites. 3) Calculating the distribution of magnetic fields at the muon site allow s us to link the $\\mu^+$SR spectra directly to the underlying magnetic st ructure. We discuss the use of this approach in skyrmion-hosting systems\, whose phase diagrams comprise several complicated incommensurate magnetic structures as a function of magnetic field and temperature. \n\n[1] B. M. Huddart *et al.* Phys. Rev. Lett. **127**\, 237002 (2021).\n[2] S. Mañas -Valero *et al.*\, npj Quantum Mater. **6**\, 69 (2021).\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3682/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3682/ END:VEVENT BEGIN:VEVENT SUMMARY:Calculating muon sites and couplings from a high-throughput modell ing perspective DTSTART;VALUE=DATE-TIME:20220828T101500Z DTEND;VALUE=DATE-TIME:20220828T103000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3686@indico.stfc.ac.uk DESCRIPTION:Speakers: Muhammad Maikudi ISAH (Department of Mathematical\, Physical and Computer Sciences\, University of Parma\, 43124 Parma\, Italy )\nIn muon spin spectroscopy\, the knowledge of muon implantation sites a nd hyperfine couplings is of importance to the analysis of the experimenta l data. Over the past decade there has been significant progress in calcul ating muon sites using first-principles methods such as density functional theory (DFT) [1\,2].  However\, the protocols required for muon calculat ions are both resource and task intensive. They are performed sequentially in steps with strenuous human intervention required to track\, coordinate and analyse these calculations. The recent advent of the DFT-based high-t hroughput (HT) approach and the development of dedicated frameworks has op ened the possibility of performing this type of sequential large-scale cal culations in an efficient way. Here\, we present our efforts towards the d esign and implementation of workflows within the AiiDA integrated platform for high-throughput DFT-based muon calculations aimed at i) the design of a user-friendly approach available to every muon user\; ii) benchmarking the scope of sustainable DFT calculations. We started from identifying mat erial selection criteria to exclude the well-known harder cases. We have b enchmarked the workflow at its current stage over 16 magnetic compounds. O ur preliminary benchmark results demonstrated the feasibility of this plan and have further allowed us to understand the workflow capabilities\, its limitations and the likely improvements to be considered for more accurat e results of the calculated muon properties. These improvements include\; taking into account the muon charge states and spotting the right comprom ise between sustainable and accurate treatment of electronic correlation e ffects.\n\n![Typical workflow results: In this case for LaFeAsO [3].][Fig1 ]\n\n[Fig1]: https://i.postimg.cc/KjyND6fp/La-Fe-As-O-fields-energy-bar-0. jpg\n\n**References**\n[1] J. S. Möller *et al.*\, Phys. Scr.\, 88\, 068 510 (2013)\n[2] P. Bonfà *et al.\,* J. Phys. Soc. Jpn\, 85\, 091014 (201 6)\n[3] M. M. Isah *et al.\,* Ph.D. thesis\, University of Parma (2022)\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3686/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3686/ END:VEVENT BEGIN:VEVENT SUMMARY:Piezoelectric-driven uniaxial pressure cell for muon spin relaxati on experiments DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3832@indico.stfc.ac.uk DESCRIPTION:Speakers: Hans-Henning Klauss (TU Dresden)\nWe present a piezo electric-driven uniaxial pressure cell operable at cryogenic temperatures and optimized for muon spin relaxation and neutron scattering experiments. These methods often require larger sample sizes\, and so the cell is desi gned to generate a force of up to ~ 1000 N. It incorporates calibrated dis placement and force sensors\, the combined knowledge of which can determin e quickly whether the sample and its mounts remain within their elastic li mits. An earlier version of this cell was presented in [1] and cells of th e current design [2] have accumulated use in multiple beamtimes [3-5]\, de monstrating its practicality. We anticipate this cell will be useful for a range of other materials\, in which the Fermi surface or magnetic interac tion strengths can be tuned leading to strong modifications of the electro nic state.\n\nReferences:\n\n[1] C. W. Hicks\, S. Ghosh et al. JPS Conf. P roc. 21\, 011040 (2018).\n\n[2] S. Ghosh et al\, Review of Scientific Inst ruments 91\, 103902 (2020).\n\n[3] V. Grinenko*\, S. Ghosh*\, et al. Natur e Physics 17\, 748-754 (2021).\n[4] Z. Guguchia et al\, Phys. Rev. Lett. 1 25\, 097005 (2020).\n[5] R. Waite et al\, arXiv:2202.11569 (2022).\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3832/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3832/ END:VEVENT BEGIN:VEVENT SUMMARY:Insights into the magnetic ground state of Fe$_2$P from $\\mu$SR\, NMR and DFT perspectives DTSTART;VALUE=DATE-TIME:20220831T080000Z DTEND;VALUE=DATE-TIME:20220831T082000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3685@indico.stfc.ac.uk DESCRIPTION:Speakers: Ifeanyi John Onuorah (Department of Mathematical\, P hysical and Computer Sciences\, University of Parma\, 43124 Parma\, Italy) \nFe$_2$P alloys have been proposed as promising for applications in magne tocaloric refrigeration due to their first-order magnetic transitions coup led to a magnetoelastic transition\, which gives rise to a giant magnetoca loric effect in the vicinity of their Curie temperature [1]. The magnetic structure of Fe$_2$P has been investigated and known to order ferromagneti cally\, with magnetic moments along the c-axis. However\, these earlier sp arse and often very old literature on Fe$_2$P are characterized by inconsi stencies in the quantitative description of the Fe$_1$ magnetic moment siz e and the presence of helical states below T$_c$. \n\nHere\, using a combi ned effort of two spectroscopic techniques\, $\\mu$SR and NMR\, in additio n to DFT calculations\, we have accurately characterized the magnetic grou nd state of Fe$_2$P. We perform zero applied field measurements using bot h experimental techniques below the ferromagnetic transition T$_C$ = 220 K [2]. Our DFT calculations reproduce the experimental results and further allow us to improve their interpretation. We show a detailed characteriza tion of the microscopic coupling between the electrons and P-nuclei or the muon in Fe$_2$P\, which where then utilized to discuss the microscopic or igin of the NMR and $\\mu$SR resonances. Particularly\, the computational predictions allow to identify correctly a previously mis-attributed signal from $^{31}$P nuclei\, an information relevant for future experiments. Th is work completely characterizes the signal of two technique of election f or the characterization of magnetic properties\, thus providing an importa nt base for further analysis of different alloy compositions.\n\nReference s\n[1] R. Hussain\, F. Cugini\, S. Baldini\, G. Porcari\, N. Sarzi Amadè\ , X. F. Miao\, N. H. van Dijk\, E. Brück\, M. Solzi\, R. De Renzi\, and G. Allodi\, Phys. Rev. B 100\, 104439 (2019).\n[2]Pietro Bonfà\, Muhammad Maikudi Isah\, Benjamin A. Frandsen\, Ethan J. Gibson\, Ekkes Brück\, I feanyi John Onuorah\, Roberto De Renzi\, and Giuseppe Allodi. Phys. Rev. Mat. 5\, 044411 (2021)\n\nhttps://indico.stfc.ac.uk/event/53/contributions /3685/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3685/ END:VEVENT BEGIN:VEVENT SUMMARY:Beta detected NMR of $^8$Li in 2H molybdenum ditelluride DTSTART;VALUE=DATE-TIME:20220902T092000Z DTEND;VALUE=DATE-TIME:20220902T094000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3684@indico.stfc.ac.uk DESCRIPTION:Speakers: Zaher Salman (Paul Scherrer Institute)\nLayered tran sition-metal dichalcogenides (TMDs) are proposed as building blocks for va n der Waals (vdW) heterostructures. Semiconducting TMDs are further prone to host magnetic impurities\, e.g. at defects or interstitials. Here we in vestigate the behavior of interstitial $^8$Li$^+$ implanted into 2H-MoTe $_2$ at depths of $\\sim$110 nm with $\\beta$-detected NMR. We find that u nlike muons $[1]$\, the $^8$Li$^+$ does not show any signature of induced magnetism. We confirm this result by density functional theory\, which id entifies the Li stopping site at the 2a Wyckoff position in the vdW gap an d shows the absence of Li-induced electronic spin polarization. Both\, the spin lattice relaxation (Fig. 1c) and the resonance lines (Fig. 1a) show evidence for Li diffusion or a site change above 200K. The line shape of $ ^8$Li$^+$ is found to consist of quadrupolar satellites on top of a broad central peak (Fig. 1a). Therefore\, we employ a frequency comb measurement \, where four frequencies\, $\\omega_0-3\\omega_{\\mathrm{comb}}$\, $\\ome ga_0-\\omega_{\\mathrm{comb}}$\, $\\omega_0+\\omega_{\\mathrm{comb}}$\, an d $\\omega_0+3\\omega_{\\mathrm{comb}}$ corresponding to the first-order q uadrupolar satellite transitions are excited simultaneously as a function of $\\omega_{\\mathrm{comb}}$. This offers an enhanced sensitivity to the quadrupolarly split portion of the line. Using this method\, we find a sma ll decrease of the quadrupolar frequency with increasing temperature (Fig. 1b)\, showing the typical behavior associated with thermally excited phon ons.\n\n$[1]$ J. A. Krieger\, et al.\, arXiv:2206.03051 (2022)\n\n![(a) $^ 8$Li$^+$ line shape and (b) frequency comb in 2H-MoTe$_2$ at different tem peratures\, which are offset for clarity. (c) Temperature dependence of th e spin lattice relaxation rate at different applied fields.][1]\n\n\n [1] : https://drive.google.com/uc?id=11a7aaRIQeaG0qFH_zgyin6MMSugmSrd5\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3684/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3684/ END:VEVENT BEGIN:VEVENT SUMMARY:Using uniaxial stress to probe the relationship between competing superconducting states in a cuprate with spin-stripe order DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3758@indico.stfc.ac.uk DESCRIPTION:Speakers: Zurab Guguchia (Laboratory for Muon Spin Spectroscop y\, Paul Scherrer Institute\, Switzerland)\nCuprate high-temperature super conductors have complex phase diagrams with multiple competing ordered pha ses. Understanding to which degree charge\, spin\, and superconducting ord ers compete or coexist is paramount for elucidating the microscopic pairin g mechanism in the cuprate HTSs. In this talk\, I will report some novel r esults of muon-spin rotation (µSR) and AC susceptibility experiments on u niaxial stress effect on the static spin-stripe order and superconductivit y in the La214 cuprates [1].\n We find that in the cuprate system La$_{2 -x}$Ba$_{x}$CuO$_{4}$ with $x$ = 0.115\, an extremely low uniaxial stress of 0.05 GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity\, from  10 to 3 2 K\; however\, the onset of at-least-2D superconductivity is much less se nsitive to stress [1] (see Figure 1a and b). These results show not only t hat large-volume-fraction spin-stripe order is anti-correlated with 3D sup erconducting (SC) coherence\, but also that these states are energetically very finely balanced. Moreover\, the onset temperatures of 3D superconduc tivity and spin-stripe order are very similar in the large stress regime. These results strongly suggest a similar pairing mechanism for spin-stripe order\, the spatially-modulated 2D and uniform 3D SC orders\, imposing an important constraint on theoretical models. \n\n[1] Z. Guguchia et. al.\, Physical Review Letters 125\, 097005 (2020).\n\nhttps://indico.stfc.ac.uk /event/53/contributions/3758/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3758/ END:VEVENT BEGIN:VEVENT SUMMARY:Monopole-limited nucleation of magnetism in Eu$_{2}$Ir$_{2}$O$_{7} $ DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3748@indico.stfc.ac.uk DESCRIPTION:Speakers: Giacomo Prando (Dipartimento di Fisica\, Università degli Studi di Pavia\, Italia)\nThe arrangement of magnetic moments at th e vertices of a pyrochlore lattice - composed of corner-sharing tetrahedra - leads to a great variety of electronic ground states for $R_{2}M_{2}$O$ _{7}$ materials. Here\, we present an in-depth analysis of muon-spin spect roscopy measurements of Eu$_{2}$Ir$_{2}$O$_{7}$ under the effect of the Eu $_{1–x}$Bi$_{x}$ isovalent and diamagnetic substitution [1] as well as o f external pressure [2]. Below $T_{N}$\, Eu$_{2}$Ir$_{2}$O$_{7}$ shows a t opologically non-trivial $4$-in/$4$-out order where the Ir$^{4+}$ magnetic moments all point inwards or outwards the tetrahedron they are located at (magnetic hedgehog monopole). Our results evidence an anomalous correlati on between the magnetic volume fraction and the order parameter only for s toichiometric Eu$_{2}$Ir$_{2}$O$_{7}$\, pointing towards highly unconventi onal properties of the magnetic phase developing therein [3]. We argue tha t magnetism in Eu$_{2}$Ir$_{2}$O$_{7}$ develops based on the nucleation of magnetic droplets at $T_{N}$\, whose successive growth is limited by the need of a continuous generation of magnetic hedgehog monopoles [3].\n\n![N ucleation of magnetism radiating from topologically non-trivial ordered te trahedra (yellow) immersed in topologically trivial paramagnetic tetrahedr a (red).][4]\n\n[1] P. Telang *et al.*\, *Physical Review B* **99** 201112 (R) (2019).\n\n[2] G. Prando *et al.*\, *Physical Review B* **93** 104422 (2016).\n\n[3] G. Prando *et al.*\, *Physical Review B* **101** 174435 (20 20).\n\n[4]: http://nmrphysics.unipv.it/wp-content/uploads/2022/07/Hedgeho g.jpg\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3748/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3748/ END:VEVENT BEGIN:VEVENT SUMMARY:Muon Sites in Hexagonal Ice DTSTART;VALUE=DATE-TIME:20220830T152000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3876@indico.stfc.ac.uk DESCRIPTION:Speakers: Amba Datt Pant (IMSS\, KEK\, Japan)\nTheoretical stu dy using density functional theory (DFT) calculations supports to estimate the stopping site of muon in materials and understand the muon spin rotat ion and relaxation ($\\mu$SR) measurements. To understand the temperature dependent zero-field (ZF) $\\mu$SR measurement in water\, we have performe d DFT calculations and quantum simulation to estimate the muon sites in he xagonal (Ih) ice. Taking initial lattice parameters from the high-resoluti on neutron powder diffraction study [1]\, the muon stopping site was calcu lated in the Ih supercell containing 2×2×1 conventional cells using Quan tum ESPRESSO [2]. The supercell contains 12 water molecules and a muon. Th e added muon in Ih ice behaves as a defect in a solid which leads to the r elaxation of immediate surrounding structure. The water molecules nearby t he muon site found reoriented. The stopping site of muon is found at aroun d 2 A distance from three protons (one proton of a water molecule and two of another\, total four spin-half (4S) system). It seems like H$_2$O-Mu-H$ _2$O$^+$ but the muon site is found neither L-defect nor D-defect but like interstitial. Based on this result and quantum simulation [4]\, only the slow-oscillating term of ZF spectra at 270 K can reproduce. To satisfy the fast-oscillating term of the ZF spectra\, quantum simulation indicates th at the muon should be at least 0.99 A distance from one of the protons in the 4S system (indicating two sites of muon). In the program\, we will pre sent DFT calculations and quantum simulations to interpret the oscillating ZF spectra at 270 K. \n\n[1] A. D. Fortes\, *Acta Crystallographica Secti on* B **74** (2018) 196.\n[2] P. Giannozzi\, et al.\, *Journal of Physics: Condensed Matter* **21** (2009) 395502.\n[3] B. G. Pfrommer\, et al.\, *J ournal of Computational Physics* **131** (1997) 233.\n[4] J. Lord\, *Physi ca B: Condensed Matter* **374-375** (2006) 472.\n\nhttps://indico.stfc.ac. uk/event/53/contributions/3876/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3876/ END:VEVENT BEGIN:VEVENT SUMMARY:TRIUMF Centre for Molecular and Materials Science Facility Overvie w DTSTART;VALUE=DATE-TIME:20220830T123500Z DTEND;VALUE=DATE-TIME:20220830T125000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3689@indico.stfc.ac.uk DESCRIPTION:Speakers: Sydney Kreitzman (TRIUMF)\nThis document breifly des cribes the mission\, governnace\, operations\, infrastructure and future d irections of TRIUMF’s CMMS. The current muon and beta-detected NMR exper imental facilites are revisted and the status of a number of pending beam line projects and spectrometer instalations are introduced.\n\nhttps://ind ico.stfc.ac.uk/event/53/contributions/3689/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3689/ END:VEVENT BEGIN:VEVENT SUMMARY:ISIS Facility Report DTSTART;VALUE=DATE-TIME:20220830T140500Z DTEND;VALUE=DATE-TIME:20220830T142000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3693@indico.stfc.ac.uk DESCRIPTION:Speakers: Peter Baker (STFC)\, Isao watanabe (RIKEN)\nThere ar e five muon instruments and two further experimental areas at ISIS includi ng RIKEN-RAL\, able to deliver both surface and decay muons appropriate fo r different experiments. Since June 2021 the whole muon facility has been in an extended shutdown as significant work has taken place on the acceler ator\, the muon collimator\, and the Target Station 1 neutron target. We n ow expect muon beams to be restored late in 2022\, with the full user prog ramme restarting in February 2023.\n\nThe major muon group project is the Super-MuSR instrument upgrade\, which is expected to be funded within the £90m Endeavour programme. This promises to bring a step-change in capabil ity\, with a highly pixelated detector and novel acquisition electronics i ncreasing the counting rate up to 20x\, and a pulse slicer and spin rotato rs increasing the available frequency range up to 10x. This will provide a bridge between the capabilities of pulsed and continuous muon sources. Pa rticular benefits will be seen by experiments that require data at long ti mes after muon implantation\, in-operando device measurements\, and parame tric studies. Other projects within the group have included refurbishing t he HiFi magnet\, adding positron degraders to EMU to improve performance\, improving the laser capabilities on HiFi\, and improving our sample envir onment equipment. \n\nDuring the shutdown there has been a full refurbishm ent of the RIKEN-RAL beamlines\, which is being carried out as part of the transition of the facility to ISIS ownership. As well as replacing obsole te services and beamline equipment\, the sample environment suite has been updated\, with new cryostats\, 3He inserts\, and dilution fridge inserts\ , to be compatible with the equipment recently acquired for the other beam lines\, improving reliability\, redundancy\, and capability. RIKEN-RAL is in high demand with the elemental analysis science programme and the FAMU proton Zemach radius now running alongside the condensed matter programme. \n\nhttps://indico.stfc.ac.uk/event/53/contributions/3693/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3693/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of ultra-slow negative muon production DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3825@indico.stfc.ac.uk DESCRIPTION:Speakers: Hiroaki Natori (KEK)\nUltra-slow negative muon produ ction is under development in J-PARC.\nIt may explore new fields in materi al science\, such as surface science\, precise depth analysis of sample ma terials after re-acceleration\, and 2 or 3 dimensional scanning of samples after re-acceleration and focusing. It may also contribute to explore new fields in Particle physics. Production of both the negative and positive ultra-slow muons will make it possible to generate undiscovered true-muoni ums and re-acceleration and focusing them may introduce muon collider.\nTh ough the ultra-slow positive muon beams are already offered or under devel opment\, the study of ultra-slow negative muon production is not intensive ly done because capture by nuclear makes it difficult.\nWe will present ab out our ultra-slow negative muon production and the current status of the development.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3825/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3825/ END:VEVENT BEGIN:VEVENT SUMMARY:What high resolution RIXS can tell us of cuprates (and of other q uantum materials) DTSTART;VALUE=DATE-TIME:20220829T094000Z DTEND;VALUE=DATE-TIME:20220829T102000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3696@indico.stfc.ac.uk DESCRIPTION:Speakers: Giacomo Ghiringhelli (Politecnico di Milano)\nResona nt Inelastic X-rays Scattering (RIXS) is an energy loss spectroscopy made with x rays whose energy is tuned to a suitable absorption edge. When the instrumental resolution is good enough\, RIXS spectra provide information on the energy\, dispersion and symmetry of local and collective excitation s\, such as ligand field excitations\, magnons and paramagnons\, phonons\, particle-hole pairs\, charge density fluctuations and order. RIXS is a po werful complement of more traditional techniques like inelastic neutron sc attering\, Raman scattering\, electron energy loss spectroscopy. \nThe ric h physics of cuprates is very effectively captured by high resolution RIXS experiments made at Cu L3 and O K edges. This fortunate conjuncture has boosted the development of better and better instrumentation at synchrotro ns and has served as one of the scientific cases for RIXS at XFELs. The fi eld is expanding and experiments are leading to more insightful results\, where the different degrees of freedom are organically studied.\nAfter int roducing the technique\, I will provide a survey of results on cuprate par ent compounds [1] and superconductors [2\,3] and on infinite layer nickela tes [4]\, which share several properties with high Tc superconductors. \n\ nReferences\n\n1. Martinelli\, L\, Betto\, D.\, et al. *Fractional spin ex citations in the infinite-layer cuprate CaCuO2*\, Phys. Rev. X **12**\, 02 1041 (2022)\n2. Arpaia\, R.\, Caprara\, S.\, et al\, *Dynamical charge den sity fluctuations pervading the phase diagram of a Cu-based high-Tc superc onductor*\, Science **365**\, 906 (2019)\n3. Peng\, Y.Y\, Martinelli\, L\, et al. *Doping-dependence of the electron-phonon coupling in two families of bilayer superconducting cuprates*. Phys. Rev. B **105**\, 115105 (2022 ).\n4. Krieger\, G.\, Martinelli\, L. et al. *Charge and spin order dichot omy in NdNiO2 driven by SrTiO3 capping layer* arXiv:2112.03341 (2021)\n\nh ttps://indico.stfc.ac.uk/event/53/contributions/3696/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3696/ END:VEVENT BEGIN:VEVENT SUMMARY:Dipolar-Octupolar Quantum Spin Liquids in Ce-based Pyrochlores DTSTART;VALUE=DATE-TIME:20220831T094000Z DTEND;VALUE=DATE-TIME:20220831T102000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3695@indico.stfc.ac.uk DESCRIPTION:Speakers: Bruce Gaulin (McMaster University)\nIn geometrically -frustrated Ce-based pyrochlores\, such as Ce$_2$Zr$_2$O$_7$\, the effecti ve S=1/2 of the Ce3+ crystal field ground state doublet is known to act bo th as a conventional dipole magnetic moment\, and as an octupole. This co nstrains the form of its near-neighbour Hamiltonian\, and allows for diffe rent ordered or quantum disordered ground states in this family of materi als\, where either the dipolar or octupolar nature of the S=1/2 degree of freedom dominates. I will describe recent experiments [1\,2]\, mostly neu tron scattering and heat capacity\, which show how the nature of the Ce3+ ground state doublet can be revealed\, and how a particular form of quantu m spin liquid can be identified as the likely ground state in Ce$_2$Zr$_2$ O$_7$.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3695/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3695/ END:VEVENT BEGIN:VEVENT SUMMARY:Challenges in next generation batteries for accelerating decarboni zation DTSTART;VALUE=DATE-TIME:20220830T084000Z DTEND;VALUE=DATE-TIME:20220830T092000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3694@indico.stfc.ac.uk DESCRIPTION:Speakers: Catia Arbizzani (Alma Mater Studiorum - Università di Bologna)\nBatteries are a key-technology for accelerating decarbonizati on. The benefits of the development of advanced batteries are enormous: br oader energy access\, specifically for off-grid communities\, the transpor t electrification that reduce the dependency from fossil fuels and the har mful local emission of nanoparticulates\, better utilization of intermitte nt energy sources [1]. Europe has decided to invest significantly in numer ous projects and initiatives: the European Commission (EC) launched the Eu ropean Battery Alliance in October 2017 to build a competitive manufacturi ng value chain in Europe for the creation of sustainable and fully recycla ble cells and batteries [2\, 3]. The EC funded the long-term research init iative Battery2030+ [4]\, thus guaranteeing accelerated support for resear ch and innovation of advanced lithium-ion batteries and disruptive technol ogies such as Li metal solid state batteries\, and the technologic platfor m Batteries Europe\, which will coordinate the efforts and the resources o f private and public partners to implement the research activities. \nWhil e Li-ion batteries will continue to play a major role in the energy storag e\, new and disruptive ideas are needed for the creation of sustainable ba tteries which pave the way to European competitiveness during the transiti on to a climate-neutral society.\n\n![Expected growth in global battery de mand by application (left) and region (right) [4]][1]\n\nReferences:\n[1] https://www.weforum.org/reports/a-vision-for-a-sustainable-battery-value-c hain-in-2030\n[2] https://ec.europa.eu/growth/industry/strategy/industrial -alliances/european-battery-alliance_en\n[3] https://www.eba250.com/\n[4] https://battery2030.eu/battery2030/about-us/challenges/\n\n\n [1]: https: //indico.stfc.ac.uk/event/53/images/140-Catia-Figure.jpg\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3694/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3694/ END:VEVENT BEGIN:VEVENT SUMMARY:Low-energy Excitations in Quantum Spin Liquid Derived from Molecul ar Mott Insulator DTSTART;VALUE=DATE-TIME:20220901T070000Z DTEND;VALUE=DATE-TIME:20220901T074000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3697@indico.stfc.ac.uk DESCRIPTION:Speakers: Reizo Kato ()\nA molecular Mott insulator ß'-EtMe$_ 3$Sb[Pd(dmit)$_2$]$_2$ (dmit = 1\,3-Dithiol-2-thione-4\,5-dithiolate) is a quantum spin liquid (QSL) candidate. In the crystal with the space group $C2/c$\, Pd(dmit)$_2$ anion radicals are strongly dimerized to form a dime r with spin 1/2. The dimers are arranged in an approximately isosceles-tri angular lattice\, which leads to a frustrated S = 1/2 Heisenberg spin syst em.\nThe system shows no magnetic order down to a very low temperature (~1 9 mK) that corresponds to $J$/12\,000\, where $J$ (~250 K) is the nearest- neighbor spin interaction energy. The HOMO-LUMO mixing in the dimer unit i nduces fragmentation of S=1/2 electron spin with strong quantum fluctuatio n.\n Low-energy excitations in the QSL state are open to debate even now. Heat capacity and magnetization indicate gapless fermion-like excitations\ , while $^{13}$C-NMR indicates an existence of a nodal gap. ESR and µSR p robed the spinons\, revealing their gapless character and an unexpectedly large degree of in-plane anisotropy in the spin dynamics. This anisotropic spin dynamics indicates quasi-one-dimensional diffusive motion in the dir ection of the weakest magnetic coupling in the triangular lattice.\n In 20 10\, it was reported that thermal conductivity is characterized by its lar ge value and gapless behavior (a finite temperature-linear term). In 2019\ , however\, two other research groups reported opposite data (much smaller value and a vanishingly small temperature-linear term) and the discrepanc y in the thermal conductivity measurement data emerges as a serious proble m concerning the ground state of QSL. An origin of the discrepancy will be discussed. \n\nI deeply thank all my collaborators\, especially\, H. Cui\ , M. Uebe\, S. Fujiyama\, Y. Oshima\, I. Watanabe (RIKEN)\, Y. Nakazawa (O saka Univ.)\, Y. Ishii (Shibaura Institute of Technology) and F. L. Pratt (STFC).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3697/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3697/ END:VEVENT BEGIN:VEVENT SUMMARY:Muons and Quantum Computing Hardware: Challenges and Opportunities DTSTART;VALUE=DATE-TIME:20220901T084000Z DTEND;VALUE=DATE-TIME:20220901T092000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3698@indico.stfc.ac.uk DESCRIPTION:Speakers: Ioan Pop (Karlsruhe Institute of Technology)\nOne mi ght wonder: what do muons have to do with quantum computing? I will argue that environmental muons and ionizing radiation in general represent a sou rce of noise and dissipation which until recently has been underestimated in the quantum devices community. I will present measurements performed in the deep-underground laboratory of Gran Sasso [1] which show a significan t improvement in the performance of superconducting quantum hardware thank s to the shielding provided by 1.6 Km of granite. On the other hand\, low energy muon beams engineered at dedicated large-scale facilities represent a powerful materials characterization tool\, and as such might play a rol e in the understanding and mitigation of material defects in superconducti ng and semiconducting quantum hardware.\n\n[1] Cardani\, Valenti et al.\, Nature Comm. 12\, 2733 (2021)\n\nhttps://indico.stfc.ac.uk/event/53/contri butions/3698/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3698/ END:VEVENT BEGIN:VEVENT SUMMARY:Introduction DTSTART;VALUE=DATE-TIME:20220828T073000Z DTEND;VALUE=DATE-TIME:20220828T073500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3703@indico.stfc.ac.uk DESCRIPTION:Speakers: Roberto De Renzi (University of Parma)\nhttps://indi co.stfc.ac.uk/event/53/contributions/3703/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3703/ END:VEVENT BEGIN:VEVENT SUMMARY:Discussion DTSTART;VALUE=DATE-TIME:20220828T085000Z DTEND;VALUE=DATE-TIME:20220828T090000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3704@indico.stfc.ac.uk DESCRIPTION:https://indico.stfc.ac.uk/event/53/contributions/3704/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3704/ END:VEVENT BEGIN:VEVENT SUMMARY:KAgF$_3$: Using F--$\\mu$--F states to measure magnetic materials DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3705@indico.stfc.ac.uk DESCRIPTION:Speakers: John Wilkinson (STFC)\nKAgF$_3$ is an antiferromagne t\, consisting of Ag ions in the rare 2+ oxidation state which magneticall y order at low temperature [1\, 2]. Here we present a detailed $\\mu$SR st udy of the compound\, showing how measuring high statistics data in the hi gh temperature\, non-magnetic phase can be used to obtain information abou t the muon site. Knowledge of the muon site then guides the analysis of th e high time resolution low-temperature data to reveal details of the magne tic ordering\, the magnetic structure and the size of the magnetic moments . We also show\, for the first time\, how the Larmor precession of the per turbed nearest-neighbour fluorine nucleus can be observed with $\\mu$SR\, as this leads to a splitting of the muon precession frequencies allowing o ne to follow the magnetic order parameter in detail.\n\n**References**\n[1 ] D. Kurzydłowski et al.\, *Chem. Commun.*\, **49** 6262 (2013).\n[2] Z. Mazej et al.\, *CrystEngComm*\, **11** 1702 (2009).\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3705/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3705/ END:VEVENT BEGIN:VEVENT SUMMARY:Yamazaki Prize Lecture - The quantum muon DTSTART;VALUE=DATE-TIME:20220829T074000Z DTEND;VALUE=DATE-TIME:20220829T082000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3702@indico.stfc.ac.uk DESCRIPTION:Speakers: Stephen Blundell (University of Oxford)\nThe key phy sical process at the heart of the muon-spin rotation ($\\mu$SR) technique is that the spin of the positive muon precesses in a local magnetic field\ , a process that can be modelled either classically (torque on a magnetic dipole) or quantum mechanically (interference between components in a supe rposition). However\, some aspects of the muon's interaction with its env ironment bring out features which are purely quantum mechanical and have n o classical analogue. Understanding this requires an accurate modelling o f the muon site\, only possible with modern electronic structure (DFT+$\\m u$) methods. I will review a variety of examples of muon experiments on o rganic\, molecular and inorganic systems which will highlight some importa nt qualities of this viewpoint and demonstrate the utitlity of "the quantu m muon".\n\n(Yamazaki lecture)\n\nhttps://indico.stfc.ac.uk/event/53/contr ibutions/3702/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3702/ END:VEVENT BEGIN:VEVENT SUMMARY:Na$^+$ self-diffusion in Co-substituted Na$_2$Ni$_2$$_-$$_x$Co$_x$ TeO$_6$ Na-ion battery cathode material DTSTART;VALUE=DATE-TIME:20220830T154000Z DTEND;VALUE=DATE-TIME:20220830T160000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3707@indico.stfc.ac.uk DESCRIPTION:Speakers: Rasmus Palm (KTH Royal Institute of Technology)\nNa$ _2$Ni$_2$TeO$_6$ honeycomb layered oxide has suitable properties for use a s a Na-ion battery cathode material. The substitution of Ni with Co has be en shown to have a detrimental effect on the energy density of Na$_2$Ni$_2 $$_-$$_x$Co$_x$TeO$_6$\, whereas the plateau potential vs Na$^+$/Na increa ses. Thus\, to ascertain the cause of the electrochemical properties chang e upon substituting Ni with Co Na-ion self-diffusion properties are invest igated with the use of zero field and longitudinal field $μ^+$SR methods in Na$_2$Ni$_2$$_-$$_x$Co$_x$TeO$_6$ with $x$ of 0.0\, 1.0 and\, 1.5. Na-i on site occupancies and crystal structure was determined from neutron powd er diffraction measurements and used for the determination of Na-ion jump paths. All measurements were performed in a temperature range from 50 K to 550 K. Three distinct Na-ion sites are determined from the neutron powder diffraction measurements. In addition\, two distinct temperature regions for Na-ion self-diffusion\, with different Na-ion diffusion pathways\, are determined and analysed. The Na-ion diffusional pathway dependence on the substitution of Ni with Co is shown and discussed. Based on the obtained results we propose a cause for the decrease in the capacity\, with the sim ultaneous increase in plateau potential vs Na$^+$/Na\, with the increased substitution of Ni with Co. Based on the results\, a roadmap on how to fur ther improve Na$_2$Ni$_2$$_-$$_x$Co$_x$TeO$_6$-based Na-ion battery cathod e materials is given.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/ 3707/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3707/ END:VEVENT BEGIN:VEVENT SUMMARY:$\\mu$SR Study of Superconductivity Above $H_{c2}$: A Filamentary State in Type-II Superconductors DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3767@indico.stfc.ac.uk DESCRIPTION:Speakers: Vladimir Kozhevnikov (Tulsa Community College)\nThe standard interpretation of the phase diagram of type-II superconductors wa s developed in the 1960s and has since been considered a well-established part of classical superconductivity. In particular\, according to the stan dard picture\, in a sample of type-II materials of a planar geometry in a parallel (in-plane) field\, superconductivity nucleates at Hc3 approximate ly twice as big as the upper critical field Hc2. Between these critical fi elds the superconducting phase exists in a form of a thin surface sheath. Contrarily\, in the same sample but in the perpendicular (out-of-plane) fi eld superconductivity nucleates in the bulk at Hc2 and there is no superco nductivity above this field. However\, upon closer examination a number of fundamental issues arises that leads one to question this standard pictur e. To address these issues\, we studied equilibrium properties of niobium samples near and above the critical field Hc2 in parallel and perpendicula r magnetic fields. The samples investigated were very high-quality films a nd single-crystal disks with the Ginzburg-Landau parameters in the range f rom 0.8 to 1.3. A set of complementary measurements has been performed\, w hich include bulk muSR\, dc magnetometry\, electrical transport and scanni ng Hall-probe microscopy. Contrary to the standard scenario\, we observed that a superconducting phase is present in the sample bulk above Hc2 and t he field Hc3 is the same in both parallel and perpendicular fields. It wil l be shown that above Hc2 the superconducting phase forms filaments parall el to the field regardless of the field orientation. Near Hc2 the filament s preserve the hexagonal structure of the preceding vortex lattice of the mixed state\, and the filament density continuously falls to zero at Hc3. \n\nReferences:\nV. Kozhevnikov\, A.-M. Valente-Feliciano\, P. Curran\, et al.\, Phys. Rev. B 95\, 174509 (2017).\nV. Kozhevnikov\, Thermodynamics o f Magnetizing Materials and Superconductors\, CRC Press\, 2019.\n\nhttps:/ /indico.stfc.ac.uk/event/53/contributions/3767/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3767/ END:VEVENT BEGIN:VEVENT SUMMARY:Photophysical dynamics in (CH$_3$NH$_3$)PbX$_3$ (X=Br\, Cl) single crystal perovskites studied by Muon-Spin Spectroscopy DTSTART;VALUE=DATE-TIME:20220830T160000Z DTEND;VALUE=DATE-TIME:20220830T162000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3709@indico.stfc.ac.uk DESCRIPTION:Speakers: Yasmine Sassa (Department of Physics\, Chalmers Univ ersity of Technology\, SE-41296 Göteborg\, Sweden)\nIn our efforts to hel p the earth recover from ecological burnout we have been trying to bridle the sun’s energy since 1954\, when the first practical silicon solar cel l was introduced. Today we are researching for ever higher efficiencies\, while we try to make use of earth-abundant materials. Perovskite solar cel ls are promising candidates for next generation photovoltaic technology du e to their energy gap tunability and significantly long carrier lifetime w hich leads to a high diffusion length.\nThis study focuses on ion diffusio n in (CH3NH3)PbX3 (X=Br\, Cl) hybrid perovskites\, structures that contain moving organic cations confined in a cage structure of PbX6 octahedra. Di ffusing ions can affect the local magnetic field distribution. We employ m uon spin spectroscopy (μ+SR) to exploit this effect by studying the relax ation of muon spin in local electronic and nuclear fields. Single crystals were studied in a 30-340 K temperature range with and without illuminatio n. We investigate the thermally activated regions\, compare the extracted diffusion rate coefficients and activation energies. However\, the dynamic al structure and structural transitions of hybrid perovskites make theoret ical interpretations challenging. With μ+SR we are able to detect these s tructural changes and study their effect on the diffusive properties of th e crystals.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3709/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3709/ END:VEVENT BEGIN:VEVENT SUMMARY:Sodium Diffusion in Hard Carbon Studied by Small-Angle Neutron Sca ttering and Muon Spin Relaxation DTSTART;VALUE=DATE-TIME:20220901T154000Z DTEND;VALUE=DATE-TIME:20220901T160000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3710@indico.stfc.ac.uk DESCRIPTION:Speakers: Kazuki Ohishi (Neutron Science and Technology Center \, CROSS)\nThe recent surge of Li-ion batteries has triggered an increased interest to investigate Na-ion battery materials [1\,2]\, because Na is m ore abundant than Li\, resulting in lower material costs. Although many Na transition metal oxides are available as a cathode material for the Na-io n battery\, there is\, at present\, no suitable anode material [1]. The mo st common anode materials for the Li-ion battery are not compatible for th e Na-ion battery\, because graphite is electrochemically inactive in an in tercalation and deintercalation reaction of Na$^+$ ions.\n\nSince non-grap hitizable carbon (hard carbon) is electrochemically active as a Na inserti on host\, hard carbon is heavily investigated as an anode material for the Na-ion battery. However\, the relationship between the structure of hard carbon and dynamics of Na insertion is still not fully clarified despite h uge efforts in the past decade [2]. We have therefore attempted to study t he microscopic structural nature of sodium intercalated hard carbon (NaC$_ x$) with small-angle neutron scattering (SANS) and the dynamics of Na diff usion in NaC$_x$ with muon spin rotation and relaxation ($\\mu^+$SR).\n\nT he transverse field $\\mu^+$SR measurements on NaC$_x$ clearly showed a mo tional narrowing behavior above around 150 K\, which indicates that Na+ st arts to diffuse above 150 K. The zero field and longitudinal field measure ments clarified the presence of the two muon sites ($\\mu$1 and $\\mu$2). Since the Na concentration around the $\\mu$1 site is higher than that aro und the $\\mu$2 site\, the $\\mu$1 site locates in the graphene layer and the $\\mu$2 site in the amorphous region [3]. At the presentation\, we wil l also discuss the results of SANS on NaC$_x$.\n\n[1] N. Yabuuchi *et al*. \, Chem. Rev. **114**\, 11636-11682 (2014).\n[2] K. Kubota *et al*.\, Chem . Mater. **32**\, 2961-2977 (2020).\n[3] K. Ohishi *et al*.\, ACS Phys. Ch em. Au **2**\, 98-107 (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contri butions/3710/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3710/ END:VEVENT BEGIN:VEVENT SUMMARY:Non-destructive elemental analysis for medical inheritances by muo nic X-ray measurement DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3784@indico.stfc.ac.uk DESCRIPTION:Speakers: Kazuhiko Ninomiya (Osaka University)\nMuon induced X -ray emission is a powerful technique for non-destructive elemental analys is for bulk material. This method have developed as practical quantitative analysis at J-PARC\, and in present\, this method have been applied for v arious samples\, such as archeological artefacts\, meteorite and so on. \n In this paper\, we report the results of applying this method to medical h eritage in Japan. About 200 years ago\, by introducing Western medicine\, many formulations in glass bottles have been left since the late Edo perio d. The analysis for these bottles are important for studying the developme nt of medicine in Japan\, but some bottles can not be opened due to aging. \nIn this study\, elemental analysis experiment using muons was conducted at J-PARC for a glass bottle that can not be open produced in the early 19 00's stored at Osaka University. By adjusting the incident muon energy\, t he muous selectively stopped inside the glass bottle\, and emitted muonic X-rays were measured by germanium semiconductor detectors. The X-ray peaks of muonic mercury and chlorine atoms were clearly observed\, and we concl uded the formulations was mainly composed of mercury chloride.\n\nhttps:// indico.stfc.ac.uk/event/53/contributions/3784/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3784/ END:VEVENT BEGIN:VEVENT SUMMARY:Operando muSR experiment on nano-cystal growing of the Fe-based ma gnetic material FINEMET(R) under external fields DTSTART;VALUE=DATE-TIME:20220829T160000Z DTEND;VALUE=DATE-TIME:20220829T162000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3711@indico.stfc.ac.uk DESCRIPTION:Speakers: Akihiro Koda (KEK/J-PARC)\nIn recent years\, there h ave been increasing opportunities to consider about energy issues on a glo bal scale\, and the development of energy-saving technologies in various f ields is highly desired. It is known that Fe-Cu-Nb-Si-B nanocrystalline al loy\, so-called FINEMET(R)\, have higher magnetic flux density\, higher li nearity\, and higher temperature stability than conventional materials. Na no-crystals of FINEMET is grown by heat treatment of Fe-based amorphous al loys\, showing different $B$—$H$ curves for various conditions of the ma gnetic field application during the heat treatment. However\, the nanocrys tallization process during heat treatment under magnetic fields has not be en fully understood. To investigate elementary processes such as grain gro wth of nanocrystals\, we have performed operando muon spin rotation experi ments. It was reported that a remarkable time variation in crystal growing under several magnetic fields is seen [M. Ohta {¥it et al}.\, JPS Conf. Proc. {¥bf 33}\, 011053 (2021)]. Recently\, more detailed analysis of tim e spectra with varying temperatures in the magnetic field has revealed the emergence of two distinct phases around the nanocrystal nucleation temper ature. It is discussed how these two phases are related to nanocrystal nuc leation and grain growth\, also using the other technique such as transmis sion electron microscope (TEM) measurements and theoretical calculations.\ n\nhttps://indico.stfc.ac.uk/event/53/contributions/3711/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3711/ END:VEVENT BEGIN:VEVENT SUMMARY:Muon Studies of the Proton Conducting Polymer Nafion DTSTART;VALUE=DATE-TIME:20220829T162000Z DTEND;VALUE=DATE-TIME:20220829T164000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3713@indico.stfc.ac.uk DESCRIPTION:Speakers: Francis Pratt (STFC)\nThe fluorinated ionomer Nafion \, first discovered by the DuPont company\, is a material that provides ef ficient proton conducting membranes for application in important technolog ical areas such as hydrogen fuel cells. Although many aspects of the polym er have been studied in relation to these applications\, the microscopic m echanisms for proton transport in this polymer are still only poorly under stood. We have therefore applied implanted muon techniques to the study of Nafion\, aiming to to gain information about these mechanisms via the muo n acting as a local spin probe. Our results indicate that the muon is high ly sensitive to the hydration state of the polymer and to the dynamical pr ocesses of the various sub-phases within the material. A three component m odel is found to describe the data well. This model has one F-$\\mu$-F com ponent reflecting muons in the PTFE-like polymer matrix\, a second compone nt representing quasi-static environments that are not closely coupled to the F atoms and a third component encompassing highly dynamic proton-coupl ed environments. The properties have been studied within this modelling fr amework as a function of temperature and hydration level.\n\nhttps://indic o.stfc.ac.uk/event/53/contributions/3713/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3713/ END:VEVENT BEGIN:VEVENT SUMMARY:Local electronic structure of interstitial hydrogen in MgH$_2$ inf erred from muon DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3714@indico.stfc.ac.uk DESCRIPTION:Speakers: Ryosuke Kadono (IMSS\, KEK)\nMetal hydrides have att racted attention as one of the candidate materials that can serve as safe and efficient hydrogen (H) storages. In particular\, MgH$_2$ has great pot ential as a solid H-storage material because of its high storage capacity of 7.6 wt\\%. However\, its slow hydrogenation and dehydrogenation rates a nd the high decomposition temperature ($\\sim$300$^\\circ$C) are major obs tacles to the practical applications. Understanding the microscopic mechan isms of the H-related processes is key to engineering solutions to improve the H-intake/release kinetics and to lower the decomposition temperature. To this end\, the information on the electronic state of interstitial H ( which exists as an intermediate state in the reaction kinetics) is crucial in gaining insight into the rate-limiting processes.\nThe preceding studi es on the microscopic state of H in MgH$_2$ have been mainly via computati onal approaches based on density functional theory (DFT)\, but there have been few experimental investigations to validate the prediction of DFT cal culations. We have introduced muons as pseudo-H into MgH$_2$\, and studied their electronic and dynamical properties in detail to elucidate the corr esponding interstitial H states. As a result\, we found two species of Mu states showing comparable yields\; a paramagnetic state with relatively la rge hyperfine parameters (0.5-1.7 GHz) that undergoes rapid conversion to diamagnetic states\, and a quasistatic diamagnetic state described by the Kubo-Toyabe relaxation function. In this talk\, we discuss the correspond ence between these Mu states and the predictions from the DFT calculations .\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3714/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3714/ END:VEVENT BEGIN:VEVENT SUMMARY:Ion Diffusion in Na Super Ionic Conductors (NaSICON) DTSTART;VALUE=DATE-TIME:20220901T162000Z DTEND;VALUE=DATE-TIME:20220901T164000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3715@indico.stfc.ac.uk DESCRIPTION:Speakers: Rasmus Palm (KTH Royal Institute of Technology)\nLit hium-ion (Li-ion) batteries are commonly used as energy storage device for both mobile and stationary applications. Even though the Li-ion technolog y is clearly a huge success story for modern electrochemistry\, lately\, t here has been serious concerns regarding several aspects\, e.g.\, availabi lity and price of lithium raw material **[1]**. Consequently\, the industr y is currently and actively looking for alternatives to the Li-ion technol ogy. Here one option might be to simply replace lithium with its neighbour in the periodic table i.e. sodium (Na) **[2]**\, which is a more abundant \, accessible and less expensive element. A famous group of such compounds is the so-called Na Super Ionic Conductors (NaSICON). One of the material s within the NaSICON family that is known to have highly mobile sodium ion s is Na$_{1+x}$Ti$_{2-x}$Fe$_{x}$(PO$_{4}$)$_{3}$ **[3]**. Electrochemical measurements have suggested that substitution of Fe for Ti results in hig her capacity and better retention. Finally\, our own studies **[4\,5]** ha ve revealed enhancements of the battery performance by introducing a nano- scale coating of carbon onto the submicron-sized NaSICON particles. Howeve r\, the underlying mechanism for such effect is still partly unknown. In t his study we have investigated the microscopic Na-ion self-diffusion in Na $_{1+x}$Ti$_{2-x}$Fe$_{x}$(PO$_{4}$)$_{3}$ using the muon spin rotation ($ \\mu^+$SR) technique **[6\,7]**. We present values of both activation ener gy of the diffusion process as well as temperature dependent Na-ion self-d iffusion coefficients ($D_{\\rm Na}$).\n\n**[1]** G. Alexander\, J.B. Good enough\, M. Månsson\, et al.\, Physica Scripta 95\, 062501 (2020) \n**[2] ** Kubota & Komaba\, J. Electrochem. Soc. 162\, A2538 (2015)\n**[3]** M.J. Aragón et al.\, J. Power Sources 252\, 208 (2014)\n**[4]** S. Difi et al .\, J. Phys. Chem. C 119\, 25220 (2015)\n**[5]** S. Difi et al.\, Hyperfin e Interact 237\, 61 (2016)\n**[6]** Sugiyama\, Månsson\, Phys. Rev. Lett. 103\, 147601 (2009)\n**[7]** M. Månsson & J. Sugiyama\, Phys. Scr. 88\, 068509 (2013)\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3715/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3715/ END:VEVENT BEGIN:VEVENT SUMMARY:The BAM cell: an electrochemical device for operando ionic diffusi on measurements using muon spectroscopy DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3716@indico.stfc.ac.uk DESCRIPTION:Speakers: Innes McClelland (University of Sheffield)\nUndersta nding the complex ways that battery materials change on charging and disch arging is vital for improving their function in operation\, but traditiona l ex-situ muon measurements have barely scratched the surface of this deep mine of information. Here\, we present an electrochemical cell that enabl es ionic diffusion measurements using muon spectroscopy (μSR) at the ISIS Neutron and Muon Source. Traditional ex-situ powder μSR measurements pro vide valuable fundamental properties\, but they often do not investigate i mportant ionic diffusion pathways which are only established during batter y operation as charge is (de)intercalated to/from the structure. Operando experiments have the potential to follow the rate of atomic-scale ionic mo tion in functioning batteries\, allowing the influence of structural pheno mena which occur during charging/discharging\, such as phase changes or la ttice contractions\, to be determined. The Battery Analysis by Muon (BAM) cell is described here as a simply assembled\, electrochemically reliable device\, which provides comparable performances to commercially available equivalent devices and can be used to study a variety of cell chemistries. The cell's suitability for μSR measurements is demonstrated by an exampl e operando experiment on a Li-ion half cell with cathode material NMC811\, which produced high quality data from the specimen of interest. This expe riment outlined the benefits of μSR to follow ionic diffusivity propertie s during charging/discharging and uncovered a link between the material ph ase transitions and the measured field distribution width. Such results fa cilitate further development of our operando methodology\, with a range of future applications of the BAM cell available for exploration.\n\nhttps:/ /indico.stfc.ac.uk/event/53/contributions/3716/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3716/ END:VEVENT BEGIN:VEVENT SUMMARY:The electron transfer channel in the sugar recognition system ass embled on nano gold particles DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3722@indico.stfc.ac.uk DESCRIPTION:Speakers: Takayuki Goto (Sophia University)\nThe recently repo rted electrochemical sugar recognition system consisting of a nano-sized g old particle (GNP) with a diameter of 10 nm\, a ruthenium complex and a ph eylboronic acid\, attracts much interest because of its high sensitivity f or various sugars such as D-glucose or D-fructose. When sugar molecules a re attached to the phenylboronic site\, the response of electrochemical vo ltammetry of the Ru site changes\, enabling the system to work as a sensit ive sugar-sensor [1]. In this recognition process\, the change in the ele ctronic state at the boron site caused by sugar must be transferred to the Ru site. However\, mechanisms of its transfer as well as the sensitivity amplification are not understood until now [2].\nWe have utilized the met hod of labelled electrons with muons and also the proton NMR to find out a channel of the electron transfer from the phenylboronic acid site to the gold nano particle via the one dimensional alkyl chain. If this transfer is driven by diffusive spin channel\, characteristic field dependence is e xpected in the longitudinal spin relaxation rate of muSR and 1H-NMR[3\,4]. We have observed significant decrease in the spin relaxation rates with increasing applied longitudinal field between 0.1 and 6 T for muSR and 1H- NMR. The result will be discussed in terms of low dimensional spin diffus ion along alkyl chains.\n\nReferences: \n[1] A. Endo et al.\, Anal. Method s\, 6\, 8874 (2014). \n[2] T. Goto et al. IEEE Trans. Mag.\, 55\, 2300404 (2019). \n[3] E. Torikai et al.\, Hyperfine. Int. 138\, 509 (2001).\n[4] F . Pratt et al.\, Phys. Rev. Lett. 79\, 2855 (1997).\n\nhttps://indico.stfc .ac.uk/event/53/contributions/3722/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3722/ END:VEVENT BEGIN:VEVENT SUMMARY:Near-surface dynamics of 1-ethyl-3-methylimidazolium acetate above and below the glass transition DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3723@indico.stfc.ac.uk DESCRIPTION:Speakers: Derek Fujimoto (TRIUMF)\nIonic liquids (ILs) are a c lass of molten salts which are liquid at room temperature. Their propertie s are determined by strong electrostatic forces and generally include low volatility\, negligible vapour pressure\, and a low melting point. This ma kes them attractive candidates for improving battery and capacitor technol ogy. The device effectiveness\, however\, is often determined by the ion a rrangement and dynamics at the interface between the IL electrolyte and th e electrode.\n\nA much simpler interface is that of the free surface (vacu um interface). Studies of IL surface chemistry reveal a number of surprisi ng phenomena\, such as orientational ordering and regions of surface cryst allization. As the ionic constituents may differ greatly in size and shape \, many ILs do not crystallize (other than at the surface\, perhaps) and w ill instead vitrify. The unusual behaviour of ILs may help to reveal novel aspects of glassy dynamics.\n\nHaving demonstrated that $\\beta$-NMR was a good probe of IL solvation dynamics and dynamic heterogeneity\,$^1$ we n ow turn to the question of how the surface modifies these properties\, pre senting the first depth-resolved $\\beta$-NMR measurements in 1-ethyl-3-me thylimidazolium acetate. The surface clearly has a large dynamical effect in the glassy phase: there is enhancement in the relaxation rate near the surface\, resembling a more liquid-like state\, yet no significant change in the dynamical heterogeneity. Additionally\, the relaxation grows faster as the material is cooled through the glass transition temperature. These two latter aspects are very surprising\, and are an extreme departure fro m the behaviour of other glasses.$^2$\n\n$^1$Fujimoto\, D. et al. Chem. Ma ter. 31\, 9346–9353 (2019).\n$^2$McKenzie\, I. et al. J. Chem. Phys. 156 \, 084903 (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3723 / LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3723/ END:VEVENT BEGIN:VEVENT SUMMARY:Search for a space charge layer in thin film battery materials wit h low-energy muons DTSTART;VALUE=DATE-TIME:20220829T154000Z DTEND;VALUE=DATE-TIME:20220829T160000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3708@indico.stfc.ac.uk DESCRIPTION:Speakers: Jun Sugiyama (CROSS Neutron Science and Technology C enter)\nIn an all solid state Li-ion battery\, it is crucial to reduce ion ic resistivity at the interface between the electrode and the electrolyte in order to enhance Li+ mobility across the interface\, because Li$^+$ ion s naturally drift across such interface. In particular\, recent first prin ciples calculations predict the presence of a space-charge layer (SCL) at the interface because of the difference in the Li$^+$ chemical potential b etween the two materials [1]\, as in the case for the interface between a metal and a semiconductor in electronic devices. However\, the presence of SCL has never been experimentally observed. We have therefore initiated s eries of studies for direct observation of SCL in different cathode batter y materials\, exploiting the unique depth-resolved features of the LEM-$\\ mu^+$SR experimental technique.\nOur first attempt in a fresh multilayer s ample\, Cu(10 nm)/Li$_3$PO$_4$(50 nm)/LiCoO$_2$(100 nm) on a sapphire subs trate\, revealed a gradual change in the nuclear magnetic field distributi on width\, originating from the nuclear fields\, as a function of implanta tion depth even across the interface between Li$_3$PO$_4$ and LiCoO$_2$. T his implies that the change in the field distribution width at SCL of the sample is too small to be detected by LEM-$\\mu^+$SR. Since the SCL is exp ected to be amplified by charge-discharge reactions\, future attempts to o bserve the space-charge layer will be conducted on multilayer samples afte r charge and discharge. \n\n[1] J. Haruyama et al.\, Chem. Mater. $\\bf{26 }$\, 4248 (2014).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3708 / LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3708/ END:VEVENT BEGIN:VEVENT SUMMARY:Shallow Muonium radical in $\\kappa$-Ga2O3 thin films. DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3571@indico.stfc.ac.uk DESCRIPTION:Speakers: Roberto De Renzi (Università di Parma)\nGa$_2$O$_3$ is an emerging wide-gap semiconductor with a broad variety of application s\, from transparent conduction to high voltage applications\, therefore c onsidered as a possible replacement for SiC. Its alpha polymorph\, which c an be grown in bulk crystalline form\, is intensely investigated. An impor tant technological development relies on the growth of thin film of the ep silon polymorph\, since the small amount of required material allows for c onsiderable cost reductions.\n\nThe role of hydrogen (H) in doping and pas sivation of vacancies\, or dangling bonds\, is very prominent in semicondu ctors\, whereas spectroscopic technique capable of detecting H are not abu ndant. Muon spin spectroscopy is unique in its ability to provide insight on the behaviour of muons as light H isotopes in the extreme dilution case \, which is impossible to access with 1H.\n\nA Muonium (Mu) shallow donor center is reported [2]\,[3] in the $\\beta$ polymorph\, with a tiny hyperf ine coupling of Bhf ~ 100 G and an activation energy for conversion to oth er muon species $E_a = 20(4)$ meV.\nHere we present the result of a surfac e muon investigation of $\\kappa$-Ga$_2$O$_3$ 30 micron-thick film grown o n sapphire. The experiment required a special kapton degrader\, obtained a fter careful tuning of its thickness\, assisted by SRIM simulations. The m easurements reveal a shallow Mu center with a similar tiny hyperfine coupl ing\, but a significantly different activation energy (see figure)\n\n [1 ]: https://univpr-my.sharepoint.com/:i:/g/personal/roberto_derenzi_unipr_i t/EXaUYBFSETxJhzzNBp_3NTQBqC7lyC6ARzlDBO_l4jVGxg?e=pa5WtZ\n\n\n[2] P. King et al.\, Appl. Phys. Lett. 96\, 062110 (2010)\n\n[3] Y.J. Celebi et al.\, Physica B 407\, 2879 (2012)\n\nLeft: $\\epsilon$-Ga$_2$O$_3$ time-depende nt asymmetry\; right: relaxation\nrate vs. temperature.\n\nhttps://indico. stfc.ac.uk/event/53/contributions/3571/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3571/ END:VEVENT BEGIN:VEVENT SUMMARY:μSR studies of dynamics in model biomembranes DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3724@indico.stfc.ac.uk DESCRIPTION:Speakers: Iain McKenzie (TRIUMF)\nAvoided level crossing muon spin resonance (ALC-$\\mu$SR) has been used to study the dynamics of the a lkyl chains and cholesterol within model biomembranes composed of phosphol ipids (DPPC and POPC) and cholesterol. ALC-$\\mu$SR is sensitive to motion s on timescales between that measurable by NMR and neutron scattering. Muo nium adds to the unsaturated C=C bonds of POPC and cholesterol to give in situ spin probes. The muon and methylene proton hyperfine coupling consta nts (hfccs) were determined from the $\\Delta_1$ and $\\Delta_0$ resonance fields in the ALC-$\\mu$SR spectra. The dipolar muon hfccs ($D_{\\mu}^{\\ parallel}$) and the electron spin flip rates were determined by modelling the $\\Delta_1$ and $\\Delta_0$ resonance lineshapes using Monte Carlo sim ulations. These parameters provide information about the motion of the spi n probes in the alkyl chains. In all cases\, the spin probes are undergoin g restricted reorientational motion\, but the addition of cholesterol lead s to more restricted motion of the alkyl chains\, evident from the larger $D_{\\mu}^{\\parallel}$\, and tighter packing of the chains\, which is ded uced from the magnitude of the muon hfccs. The goal of this project is to determine how the dynamics at different positions within the biomembrane d epend on the composition.\n\nhttps://indico.stfc.ac.uk/event/53/contributi ons/3724/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3724/ END:VEVENT BEGIN:VEVENT SUMMARY:Unconventional superconductivity in topological ruthenium silicide s with Kramers and hourglass fermions DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3760@indico.stfc.ac.uk DESCRIPTION:Speakers: T. Shiroka (Laboratorium für Festkörperphysik\, ET HZ)\nThe convergence of two major research strands in modern condensed-mat ter physics: topological materials and unconventional superconductivity\, constitutes a new field of study. Topological materials with Kramers or ho urglass fermions represent a special subclass\, recently realized in mater ials lacking inversion symmetry or with a nonsymmorphic space group. At th e same time\, there is a surge of interest in identifying time-reversal sy mmetry (TRS) breaking (a key feature of unconventional superconductivity) in this class of materials\, as a new routine way to realize topological s uperconductivity. \n\nBy using the muon-spin rotation and relaxation techn ique\, backed by detailed theoretical analyses\, we show that TRuSi (*T* = Ti\, Nb\, Hf\, and Ta) noncentrosymmetric materials represent a family of compounds encompassing all the above unique properties [1]. Their bulk no rmal states behave as three-dimensional Kramers nodal-line semimetals\, ch aracterized by a fairly large antisymmetric spin-orbit coupling and by gli de-reflection-protected hourglass-like fermions. We also identify surface states near the Fermi level of TRuSi materials More interestingly\, NbRuSi and TaRuSi undergo a superconducting transition\, which spontaneously bre aks TRS below $T_c$\, while surprisingly showing a fully-gapped supercondu cting ground state. This superconducting ground state is consistent with a unitary (*s* + *ip*) pairing\, i.e.\, with a mixture of spin-singlet and spin-triplet pairings. As such\, the TRuSi family provides an ideal platfo rm for investigating the rich interplay between the exotic properties of K ramers nodal-line/hourglass fermions and unconventional superconductivity. \n\n[1] T. Shang\, J. Z. Zhao\, et al.\, and T. Shiroka\, submitted to *Sc i. Adv.* (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3760/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3760/ END:VEVENT BEGIN:VEVENT SUMMARY:Tribute to Jun Kondo DTSTART;VALUE=DATE-TIME:20220830T143000Z DTEND;VALUE=DATE-TIME:20220830T143500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3881@indico.stfc.ac.uk DESCRIPTION:Speakers: Ryosuke Kadono (KEK IMSS)\nhttps://indico.stfc.ac.uk /event/53/contributions/3881/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3881/ END:VEVENT BEGIN:VEVENT SUMMARY:Quadrupolar split resonance of $^{8}$Li in LaAlO$_3$ DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3726@indico.stfc.ac.uk DESCRIPTION:Speakers: Victoria Karner (TRIUMF)\nLaAlO$_3$ is a wide bandga p\, transparent oxide commonly used as a substrate for epitaxial film grow th and as a vacuum-like electrically insulating layer in heterostructures. Below a soft-mode structural phase transition at about 800 K\, it is rhom bohedrally distorted from the ideal cubic perovskite structure as the AlO$ _6$ octahedra rotate about the cubic $\\langle 111 \\rangle$ directions$^1 $. It is a popular substrate\, in part\, because Al does not support multi ple oxidation states like Ni or Ti and because it is well matched to mater ials such as LaNiO$_3$ due to the similarity of their lattice constants. H ere\, we establish the behaviour of $^8$Li in the bulk as a prerequisite t o probing the surface effects of the rhombohedral distortion$^2$.\nWe repo rt $\\beta$-detected NMR of $^{8}$Li$^{+}$ implanted into a single crystal of rhombohedral LaAlO$_3$. Like other insulating perovskites$^{3}$\, the resonance is quadrupole split\, since even in the cubic phase\, its inters titial site (the $P$-site\, Wyckoff $3d$ in the cubic phase) is noncubic. In fact\, the splitting in the perovskites$^4$ is the largest observed for $^8$Li. The splitting is comparably large in LaAlO$_3$ ($\\nu_q \\approx $ 191.3 kHz)\, but there is additional splitting due to the rhombohedral d istortion.\n1. The transition has been studied in some detail by conventio nal NMR\, see e.g.\, F. Borsa et al\, Phys. Lett. A 34\, 5 (1971).\n2. For example\, see the case of SrTiO$_3$\, Z. Salman et al.\, Phys. Rev. Lett. 96\, 147601 (2006)\n3. V. L. Karner et al.\, JPS Conf. Proc. 21\, 011024 (2018)\n4. This has proven useful for refining the value of the nuclear qu adrupole moment\, see e.g.\, A. Voss et al.\, J. Phys. G: Nucl. Part. Phys . 41\, 015104 (2014)\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3 726/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3726/ END:VEVENT BEGIN:VEVENT SUMMARY:Unfolding of the depth profiles with universal-range distribution functions DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3731@indico.stfc.ac.uk DESCRIPTION:Speakers: Eduardo Ribeiro ()\nThe analysis of depth-dependent data of thin-film film semiconductor heterostructures is discussed in this work. The data is obtained by varying muon implantation energy\, E\, usin g the Low Energy Muon facility (LEM) at PSI\, Switzerland. Since the measu rement method has a finite resolution\, deconvolution of the measured prof ile with the resolution function is required. The unfolding can be implem ented in the real space (that is in depth variable x)\, using range distri bution function\, P(x\,E)\, obtained by Monte Carmo simulations. The unfol ding in depth space requires detailed knowledge of the sample which may no t be available. It is shown that it is much simpler to start by performing the deconvolution in the implantation energy space and to transform it af terwards into real space. This requires transforming P(x\,E)\, in P(E’\, E) by an adequate variable change x = f(E'). The best approach is to use t he relation between the median and the implantation energy for the coordin ate transformation\, since it ensures that the range distribution is cente red at the implantation energy E. The range distributions in energy space\ , as derived from the depth distributions in CdS\, are depictured in the F ig.1. They are considered nearly universal for all materials.\n\n![Univers al range distributions in energy space for different implantation energies .][1]\n\n\n [1]: http://algol.fis.uc.pt/muon/range_distribution_Fig.jpg\n \nhttps://indico.stfc.ac.uk/event/53/contributions/3731/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3731/ END:VEVENT BEGIN:VEVENT SUMMARY:Non-destructive Elemental Analysis of Lunar Materials with Negativ e Muon Beam at J-PARC DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3787@indico.stfc.ac.uk DESCRIPTION:Speakers: I-Huan Chiu (Osaka University)\nA muonic atom is for med when a muon is captured in an atom system\, and characteristic muonic X-ray emission occurs with the muon deexcitation process. The chemical com position of a material can be known based on the intensities of the emitte d muonic X-rays. Non-destructive elemental analysis using negative muon be am has been highly developed in the last decade. This method provides a po werful tool to determine the material composition of meteorites without ca using damage.\n　　We performed a muon experiment at the D2 muon beamlin e of the Muon Science Establishment (MUSE) in the Japan Proton Accelerator Research Complex (J-PARC). Three lunar meteorite samples (NWA482\, NWA032 \, DEW12007) were wrapped with 12.5 μm Kapton foil and installed in a sta inless steel analysis chamber filled with Helium gas. The total exposure t ime of muon irradiation with a momentum of 27 MeV/c for each sample was ar ound 10 hours\, and the emitted muonic X-rays were observed by six low-ene rgy high-purity germanium semiconductor detectors\, which were installed a round the samples.\n　　The peaks with energies of 76.7\, 89.2\, 92.7\, 54.8\, and 56.4 keV were clearly observed in the energy spectrum and were identified as the muonic X-rays from Si\, Al\, Fe\, Ca\, and Mg\, respecti vely. The intensities of these muonic X-rays were determined by data fitti ng with gauss functions. Because the self-absorption of the sample and the detection efficiency of germanium semiconductor affect the measurement\, the corrections based on the Monte-Carlo simulation were also applied in t his study. \n　　We successfully defined the chemical comparison of elem ent/Si ratios of three lunar meteorites based on quantitative analysis for muonic X-ray measurement. The observed chemical composition suggests that the DEW12007 (polymict regolith breccia) could be a mixture of basaltic c rust (NWA032-like) and anorthositic crust (NWA482-like) in terms of Al\, F e\, Ca\, and Mg contents.\n\nhttps://indico.stfc.ac.uk/event/53/contributi ons/3787/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3787/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigation of doping and dopant dependence of n-type 4H-SiC wit h low-energy muon spin spectroscopy DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3729@indico.stfc.ac.uk DESCRIPTION:Speakers: Maria Mendes Martins (Laboratory for Muon Spin Spect roscopy\, Paul Scherrer Institute)\nSilicon carbide (4H-SiC) is a wide-ban dgap semiconductor with applications in high power devices. Epitaxial grow th of SiC is crucial to produce structures with controlled thickness and d oping concentration. Ion implantation with nitrogen (N) and phosphorus (P) \, on the other hand\, is used to create spatially defined n-type regions in SiC. Implantation is usually followed by a post-implantation annealing step\, to ensure lattice recovery and electrical activation of the donors. However\, mitigating implantation-induced defects remains a challenge.\n\ nThe narrow defective regions$\\\;$(200-300$\\\;$nm) are not accessible by conventional techniques\, but can be studied with low-energy muon-spin sp ectroscopy (LE-$\\mu$SR). The LE-$\\mu$SR experiments were performed at th e low-energy muon facility at the S$\\mu$S (PSI\, Switzerland). The 4H-SiC samples were either doped with N during epitaxial growth$\\\;$(N$_D=4\\ti mes$10$^{15}\\\;$and$\\\;1\\times$10$^{17}\\\;$cm$^{-3}$)$\\\;$or using io n-implantation of N and P$\\\;$(N$_D=1\\times$10$^{17}\\\;$and$\\\;1\\time s$10$^{18}\\\;$cm$^{-3}$). The goal was to compare the different doping pr ocesses and to establish a $\\mu$SR baseline for different doping concentr ations in n-type SiC.\n\nWe find that an effective electron concentration (*n*)$\\\;$of$\\\;4\\times$10$^{15}\\\;$cm$^{-3}$ in SiC is below the sens itivity limit of LE-$\\mu$SR. For N$_D>$1$\\times$10$^{17}\\\;$cm$^{-3}$\, there is an intermediate space charge region where muonium (Mu$^0$) forma tion dominates and the diamagnetic fraction (F$_D$) decreases. In the deep er probed region\, F$_D$ increases with doping concentration due to Mu$^-$ formation. F$_D$ also increases between $10\\\;$and$\\\;0.5\\\;$mT indica ting delayed Mu$^-$ formation\, having a Mu$^0$ precursor state. For the i mplanted samples\,$\\\;10\\\;$K measurements indicate higher defect densit y for$\\\;1\\times$10$^{18}\\\;$cm$^{-3}$\, which can be related to the hi gher implantation dose. \nFurthermore\, Monte Carlo simulations were used to generate muon decay histograms for different electron capture rates\, t o determine F$_D$ and the phase of the diamagnetic signal as function of * n*\, which agree with the experimental results. This means\, that *n* can be determined for a SiC sample with unknown carrier concentration by compa ring the experimental results of F$_D$ and the phase with the results of the simulation.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3729/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3729/ END:VEVENT BEGIN:VEVENT SUMMARY:Analysis of Positively Charged Muonium in Tin Oxide DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3730@indico.stfc.ac.uk DESCRIPTION:Speakers: Brittany Baker (Francis Marion University)\nTin oxid e is a transparent conducting oxide (TCO) that has many applications in op toelectronic devices\, such as solar cells and LED’s. Tin oxide is natur ally n-type with hydrogen acting as a shallow donor. MuSR zero-field measu rements were taken on a single crystal sample from 2 K to 710 K in a close d cycle refrigerator and from 300 K to 1080 K in an optical furnace. The z ero-field measurements allow for analysis of positively charged muonium de fects in samples. The analysis of the results shows two positive muonium s tates with hints of an additional state at temperatures below 300 K. The c urrent model shows a high occupancy positive muonium state and a low occup ancy positive muonium state with a slow migration of muonium from the high occupancy state to the low occupancy state above 300 K. We will present d etails of an updated model and the muonium sites\, energies barriers\, and diffusion processes of the positively charged muonium determined from the model.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3730/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3730/ END:VEVENT BEGIN:VEVENT SUMMARY:Hydrogen impurity in MgO as seen by the muonium analogue DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3725@indico.stfc.ac.uk DESCRIPTION:Speakers: Ali Roonkiani (CFisUC\, Department of Physics\, Univ ersity of Coimbra)\nWe present a joint muSR and ab-initio study of the hyd rogen impurity in magnesium oxide (MgO). Muon spin rotation measurements a t magnetic high-fields reveal the presence of a diamagnetic configuration and of a muonium state\, confirming an hyperfine interaction of 3.9(1) GHz at T=6K [1]. The temperature dependence of these states is followed up to room temperature\, revealing a conversion of the muonium to the diamagnet ic state. Ab-initio density-functional theory (DFT) calculations further c haracterize the local atomistic (or microscopic) structure of these two co nfigurations\, the atomic muonium state corresponding to an interstitial l ocation in the magnesium oxide lattice and the diamagnetic configuration c orresponding to an oxygen-bound location.\n\n[1] R. F. Kiefl et al.\, Phys . Rev. B 34 (1986) 1474\n\n![FFT of MuSR spectrum of MgO at T=6K and B=2T. ][1]\n\n\n\n [1]: http://algol.fis.uc.pt/muon/FFT_Fig.jpg\n\nhttps://indi co.stfc.ac.uk/event/53/contributions/3725/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3725/ END:VEVENT BEGIN:VEVENT SUMMARY:An updated model for muonium in 6H-SiC DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3732@indico.stfc.ac.uk DESCRIPTION:Speakers: Rick (P.W.) Mengyan (Northern Michigan University)\n We present an updated model for muonium properties and behavior in silicon carbide (polytype 6H\; SiC) based on new (unpublished) and published resu lts from our group’s TF-\, LF-\, RF- and photoexcited MuSR measurements. \nSiC is known and widely used for structural ceramics due to its physica l properties (e.g. high thermal conductivity\; hardness\; strength\; resis tance to corrosion and abrasion) all being stable to near ~1920 K. The el ectrical and optical properties (E$_{\\textrm{G}}$ ~3.0 eV\, for 6H-SiC) o f SiC are of great interest to the device community as\, for example\, its electrical resistivity can be tuned from high resistivity (intrinsic) to a more conductive variety via p− or n− type doping. Isolated hydrogen impurities in semiconductors is an unavoidable\, abundant and electrically active impurity in many materials. Direct study of isolated hydrogen impu rities in semiconductors is not generally possible due to hydrogen’s hig h reactivity or solubility limitations within the host\; however\, muonium is an experimentally accessible analogue allowing for an investigation in to the stability and dynamics of these impurity centers.\nOne of the most popular polytypes of SiC is a 6 layer\, hexagonal (Wurtzite\; 6H-SiC). In this polytype\, T-sites with Si neighbors at the end of a short-c axis hav e estimated hyperfine constants of 3009.5 MHz (Mu1) and 3026 MHz (Mu1b). A Si antibonding site has an estimated hyperfine constant of 2768 MHz (Mu2) . A carbon antibonding site is identified with an estimated hyperfine cons tant of 2801 MHz (Mu3). Donor and acceptor levels were initially estimated based on thermal ionization\; later\, laser-based measurements identified possible ionization energies with some of these states. LF- and RF- MuSR has been completed to develop the most complete available characterization of muonium states in 6H-SiC.\n\nhttps://indico.stfc.ac.uk/event/53/contri butions/3732/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3732/ END:VEVENT BEGIN:VEVENT SUMMARY:β-NMR studies of the temperature\, depth and molecular weight dep endence of dynamics in normal and ultrastable polystyrene glasses DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3717@indico.stfc.ac.uk DESCRIPTION:Speakers: Iain McKenzie (TRIUMF)\nThe observation that the gla ss transition temperature of polystyrene (PS) thin films decreases with de creasing film thickness led to the suggestion that there is a very thin la yer near the free surface where the polymer motion is faster than in the b ulk. Direct confirmation of enhanced dynamics near the free surface has pr oved elusive as few techniques can measure how the dynamics varies with di stance from the free surface on the nm length scale and those that can eit her use bulky probes or multilayer films that modify the dynamic gradients . Implanted $^8$Li$^+$ is a much less perturbing probe and with $\\beta$-d etected nuclear magnetic resonance ($\\beta$-NMR) we can measure the depth dependence of the $\\gamma$ relaxation of PS\, which involves motion of t he phenyl side groups.$^{1\,2\,3}$ The $\\gamma$ relaxation has a double e xponential depth dependence from the free surface\, with a characteristic length of ~6 nm. We have produced ultrastable glass (USG) films of low-mol ecular weight PS by physical vapor deposition that exhibit properties simi lar to those of a normal glass (NG) that has been aged for several years. Our β-NMR measurements indicate the bulk $\\gamma$ relaxation is slower i n the USG compared with the NG while the opposite is true near the free su rface where the $\\gamma$ relaxation is faster in the USG compared with th e NG. These trends are more significant for samples with a larger apparent age. \n1. I. McKenzie et al.\, *Soft Matter* **2015**\, *11*\, 175\n2. I . McKenzie et al.\, *Soft Matter* **2018**\, *14*\, 7324\n3. I. McKenzie e t al.\, *J. Chem. Phys.* **2022**\, *156*\, 084903\n\nhttps://indico.stfc. ac.uk/event/53/contributions/3717/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3717/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muons for the characterization of thin layers in Cultural Heritage artefacts DTSTART;VALUE=DATE-TIME:20220829T140000Z DTEND;VALUE=DATE-TIME:20220829T142000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3802@indico.stfc.ac.uk DESCRIPTION:Speakers: Matteo Cataldo ()\nMuonic X-ray Emission Spectroscop y (µXES) is a novel technique based on the detection of high-energy X-ray s emitted after the interaction of a negative muon beam with matter. Thank s to the multi-elemental range\, a negligible self-absorption effect of th e x-rays and very low residual activity left in the sample after irradiati on\, the technique has been applied to a wide range of studies\, with spec ial attention to cultural heritage artefacts. In addition\, the technique offers the possibility to perform depth profile studies. By tuning the ene rgy of the incident muon beam\, indeed\, it is possible to investigate the different layers that constitute a sample. Here we report preliminary res ults of the analysis on two fire-gilded surfaces\, in which the gold layer was supposed to be around 10 microns. In particular\, in this work\, the technique is coupled with a Monte Carlo based simulation software. Simulat ions are a powerful tool for improving the data analysis and the interpret ation: for µXES especially\, by exploiting a simulation software like SRI M or GEANT4\, it is possible to assess the thickness of a given layer. To perform a depth profile characterization\, the samples were analysed at di fferent beam energies (or momentum). Each of the resulting x-ray spectra w as then analysed and gaussian fitted with a data analysis software. Then\, the normalised area values were plotted against the momentum to obtain a profile of the variation of the elements as the penetration depth of the b eam increased. The output of the simulations was compared with the experim ental data and a remarkably good agreement was reached. The results of the work are promising and with this approach\, it will be possible to enhanc e the capability offered by the technique both in terms of data analysis a nd data interpretation.\n\nhttps://indico.stfc.ac.uk/event/53/contribution s/3802/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3802/ END:VEVENT BEGIN:VEVENT SUMMARY:Local electronic structure of dilute hydrogen in gallium oxide DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3734@indico.stfc.ac.uk DESCRIPTION:Speakers: Masatoshi Hiraishi (Ibaraki University)\nGallium oxi de $\\beta$-Ga$_2$O$_3$ is currently drawing much attention as a material for high-voltage power devices because of its large band gap ($E_\\mathrm{ g}\\sim$4.9 eV). We investigated the electronic structures of muon as a ps eudo-hydrogen in $\\beta$-Ga$_2$O$_3$ in which the dilute hydrogen is unde r the central focus as a crucial factor for the bulk conducting properties . We demonstrate by $\\mu$SR study combined with the first principles calc ulations that muons in $\\beta$-Ga$_2$O$_3$ have two electronic structures : a state corresponding to hydrogen that acts as an electron donor (Mu$_1$ )\, bounded to three-coordinated oxygen\, and a hydride-like state in rapi d motion (Mu$_2$). Furthermore\, we imply from the Hall effect measurement s that the fractional yield of Mu$_2$ exhibits a close link with the mobil ity and density of the carriers (electrons).\nIn the presentation\, we wil l compare our results with those of previous study and discuss the electro nic structures of Mu$_1$ and Mu$_2$ in terms of our recently proposed ambi polar model of muon in oxides.\n\nhttps://indico.stfc.ac.uk/event/53/contr ibutions/3734/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3734/ END:VEVENT BEGIN:VEVENT SUMMARY:Analysis of Positively Charged Muonium and its Diffusion in Cadmiu m Oxide DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3735@indico.stfc.ac.uk DESCRIPTION:Speakers: Samuel Cathcart (Francis Marion University)\nCadmium oxide is a transparent conducting oxide (TCO) that has many applications in optoelectronic devices\, such as solar cells\, photo transistors and di odes. CdO is a naturally n-type TCO with hydrogen acting as a shallow dono r. MuSR zero field measurements were collected\, from 20 K to 800 K\, to i nvestigate the diffusion properties of positive Mu defects in a CdO powder sample. The neutral Mu shallow donor signal is seen up to 200 K. At this temperature the neutral Mu ionizes. The calculated ionization energy is 11 9 meV +/- 20 meV. This result in agreement with Cox\, et. al. [*J. Phys.: Condens. Matter* **18**\, 1061 (2006)]. Two positive Mu sites are seen bel ow 425 K. Above 425 K\, one of the positive Mu sites becomes mobile and tr ansitions to the second positive Mu site. By 550 K\, all positive Mu have transitioned to the second site. Details relating to the transition betwee n sites\, barrier energies\, and diffusion processes will be discussed in the presentation.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3735 / LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3735/ END:VEVENT BEGIN:VEVENT SUMMARY:Anisotropic hyperfine coupling of muonium in CeO$_2$ studied by mu on spin relaxation DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3733@indico.stfc.ac.uk DESCRIPTION:Speakers: Akihiro Koda (KEK/J-PARC)\nCeO2 is a material that h as been widely used in industrial fields such as catalysts and sensors. It is believed that oxygen deficiencies and hydrogen at the deficient positi ons play an important role in these functions\, but the details\, includin g the electronic state\, have not been clarified. It has been reported tha t muons implanted in CeO2 are bound to electrons and form muonium [S.F.J.C ox *et al*.\, J. Phys.: Condens. Matter **18**\, 1079-1119 (2006)]. Howeve r\, the sample used in the experiment was a powder\, and the information a bout the oxygen deficiency in the measured sample is unknown. Therefore\, we perform the muon experiment using a single crystal sample. By using a s ingle crystal\, we can deduce the oxygen deficiency from other measurement technique\, and by combining this information with our result of muon exp eriments\, we can clarify the details of the electronic state of hydrogen in CeO2.\nIt was seen in our muon experiments that muon spin relaxation su ggesting the existence of muonium in single crystals of CeO2 appears at te mperatures below ~60 K under zero external field. The temperature dependen ce is qualitatively in good agreement with that reported by Cox *et al*. A s the longitudinal magnetic field along the [100] crystalline axis being i ncreased\, the spin polarization at *t* = 0 recovered. It is noted\, howev er\, that the obtained magnetic field dependence of the spin polarization at *T* = 9 K is different from the behavior expected for muonium with isot ropic hyperfine coupling\, strongly suggesting the anisotropy of the hyper fine coupling constant at the muon stopping site. Furthermore\, we observe d how the anisotropic behavior seen in longitudinal magnetic fields change s with changing the crystal orientation\, taking advantage of the single c rystal sample. From these results\, we discuss the position of muonium in the crystal lattice and its electronic state.\n\nhttps://indico.stfc.ac.uk /event/53/contributions/3733/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3733/ END:VEVENT BEGIN:VEVENT SUMMARY:Confirming the phase diagram of the Shastry-Sutherland model with $\\mu^+$SR DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3737@indico.stfc.ac.uk DESCRIPTION:Speakers: Yuqing Ge (Chalmers University of Technology)\nOne f amous model for a two-dimensional magnetic system is the Shastry-Sutherlan d (SS) model\, which considers an orthogonal dimer network of spin S = 1/2 [1]. The model predicts a dimer ground state for J/J’ 1 [2]. However\ , the ground state of the intermediate region (0.5 \n\nhttps://indico.stfc .ac.uk/event/53/contributions/3737/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3737/ END:VEVENT BEGIN:VEVENT SUMMARY:The interaction between positive muons and multiple quadrupolar nu clei DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3741@indico.stfc.ac.uk DESCRIPTION:Speakers: Stephen Blundell (University of Oxford)\nA positivel y charged muon implanted in copper sits at an octahedral interstitial site and experiences a magnetic dipolar coupling with six nearest-neighbour qu adrupolar $I=3/2$ copper nuclei [1]. The resulting avoided level crossing resonance observed as a function of magnetic field [2] provides a means o f studying these interactions and understanding the effect of the electric -field gradient due to the muon experienced by the quadrupolar nuclei. Th e effect is usually modelled by considering the interaction between the po sitive muon and a single copper nucleus\, but the other five copper nuclei are equally important. By solving the problem in the full $2(2I+1)^6=819 2$-dimensional Hilbert space\, we demonstrate the effect of these addition al interactions.\n\n[1] M. Camani\, F. N. Gygax\, W. Ruegg\, A. Schenck\, and H. Schilling\,\nPhys. Rev. Lett. 39\, 836 (1977).\n\n[2] G. M. Luke\, J. H. Brewer\, S. R. Kreitzman\, D. R. Noakes\, M. Celio\,\nR. Kadono\, E. J. Ansaldo\, Phys. Rev. B 43\, 3284 (1991).\n\nhttps://indico.stfc.ac.uk/ event/53/contributions/3741/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3741/ END:VEVENT BEGIN:VEVENT SUMMARY:Probing Local Magnetic Order in the Frustrated Bow-tie Lattice of Layered Oxide Ca$_2$Mn$_3$O$_8$ DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3743@indico.stfc.ac.uk DESCRIPTION:Speakers: Holly L. McPhillips (University of Kent)\nFrustrated magnetism continues to be a vibrant area of research in chemistry and con densed matter physics. Geometric frustration arises when the magnetic degr ees of freedom are incompatible with the underlying lattice geometry\, and contrasts conventional magnetism because the system exhibits numerous deg enerate ground states. Hence\, rich exotic phenomena are observed as a fun ction of pressure and (or) temperature. A plethora of frustrated layered o xide materials exist\, including the delafossite family which is similar t o the well-known Kagomé system and is based on a triangular antiferromagn et. One variant of this family with interesting bow-tie connectivity is Ca $_2$Mn$_3$O$_8$\, which contains two unique manganese sites. It exhibits t wo magnetic phase transitions\, one at T$^*$ = 130 K that is associated wi th short-range spin correlations and a second at T$_N$ = 58 K that is asso ciated with three-dimensional long-range order. From neutron diffraction s tudies\, the former transition is exclusively linked to the crystallograph ic *b*-direction but fully ordered one-dimensional chains are not realised . To further investigate this interesting local magnetic behaviour\, tempe rature studies using inelastic neutron scattering\, X-ray absorption spect roscopy and muon spin spectroscopy were carried out. Measurements reveal t he intriguing correlation between the unique manganese sites such that sta tic-dynamic behaviour between both persists below T$^*$ in an attempt to r elieve frustration.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/37 43/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3743/ END:VEVENT BEGIN:VEVENT SUMMARY:Simulating muon spin depolarisation in a nanostructured magnetic m aterial DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3745@indico.stfc.ac.uk DESCRIPTION:Speakers: Rhea Stewart (ISIS Muon Group\, STFC\, UK)\nArtifici al spin ices\, which are composed of dipolar coupled arrays of elongated n anomagnets\, host a broad range of physical phenomena usually the preserve of bulk condensed matter[1]. In particular\, collective phase transitions between ordered and disordered states have been well documented in these nanomagnetic systems[2]. The complex phases observed in artificial spin ic es occur as a consequence of dipolar interactions between neighbouring mag netic moments. In order to better control the collective behaviour of the spins one must tune the interactions between nanomagnets. Traditionally th is has been achieved by either varying the lengthscales within the lattice or by altering the dimensions of the individual nanomagnets themselves. H owever\, when one pushes to smaller dimensions direct imaging techniques c an no longer be used to characterise the phase transitions due to limitati ons in resolution. \n\nIn recent years\, low energy muon spin relaxation h as been used to great effect in order to study the behaviour of artificial spin systems[3]. Here we present our recent work on modelling the muon sp in depolarisation in nanostructured magnetic materials. We use Monte Carlo simulations to compute the static nanomagnet moment configurations\, and from these configurations calculate the net stray field distribution at th e muon site. Muons are then implanted and their spin evolution determined *via* solution of the Landau-Lifshitz precession equations. By performing a full spatial integration over the plane of the sample and the muon stopp ing profile\, we are able to simulate experiment[4].\n\n[1]. S. H. Skjærv œ et. al. Nat. Rev. Phys.\, 2019\n[2]. O. Sendetskyi et. al. Phys. Rev. B \, 2019\n[3]. N. Leo et. al. Nat. Communs.\, 2018.\n[4]. R. Stewart et. al . In Preparation\, 2022\n\nhttps://indico.stfc.ac.uk/event/53/contribution s/3745/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3745/ END:VEVENT BEGIN:VEVENT SUMMARY:Current Status of Operando-$\\mu^+$SR for Battery Materials at J-P ARC DTSTART;VALUE=DATE-TIME:20220829T152000Z DTEND;VALUE=DATE-TIME:20220829T154000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3706@indico.stfc.ac.uk DESCRIPTION:Speakers: Kazuki Ohishi (Neutron Science and Technology Center \, CROSS)\nIon transport in solids is a key feature for the operation of i on batteries. There are two parameters for describing ion transport in bat tery materials\; one is a self-diffusion coefficient ($D^J$) and the other is a chemical diffusion coefficient ($D^C$). The former diffusion is caus ed by thermally activated fluctuation of ions\, while the latter diffusion is caused by a flow due to a concentration gradient of ions. Majority of work concerning battery materials\, $D^C$ has been measured with an electr ochemical technique under a concentration gradient of the ion in a half-ce ll. $D^C$ is then estimated using the relationship: $D^C=\\Theta D^J$\, in which $\\Theta$ denotes a thermodynamic factor.\nAccording to the Cottrel l equation\, the time evolution of the current of the planer electrode in the half-cell under an ion-concentration-gradient has a relation\, $I(t)\\ propto A_{re}\\sqrt{D^C}C$\, where $A_{re}$ and $C$ denote the reactive su rface area of the electrode and the concentration of the ion. Thus\, the o btained value from the electrochemical measurement is not $D^C$ but $D^C A _{re}^2$. Because the correct $A_{re}$ in liquid or solid electrolytes is unknown\, it is very difficult to determine $D^C$. We have thus initiated series of experiments to measure intrinsic $D^J$ of battery materials with $\\mu^+$SR [1]. Due to the change in the crystal structure and occupancy of a regular Li site with SOC\, $D^J$ is predicted to depend on SOC [2]. T herefore\, it is highly desirable to measure $D^J$ as a function of SOC un der working condition\, namely\, an operando $\\mu^+$SR. We are attempting to establish such technique in J-PARC\, and show the current status.\n\n[ 1] For example\, J. Sugiyama et al.\, Phys. Rev. Lett. 103\, 147601 (2009) .\n[2] A. Van der Ven and G. Ceder\, Electorchem Solid-State Lett. 3\, 301 (2000).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3706/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3706/ END:VEVENT BEGIN:VEVENT SUMMARY:Phase transition from a magnetic-field-free stiffness meter and LE M viewpoints DTSTART;VALUE=DATE-TIME:20220901T092000Z DTEND;VALUE=DATE-TIME:20220901T094000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3774@indico.stfc.ac.uk DESCRIPTION:Speakers: Amit Keren (Technion Israel Institute of Technology) \nA new method to measure the superconducting stiffness tensor ${\\bar \\r ho _s}$\, without subjecting the sample to magnetic field\, is applied to La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) [1]. The method is based on the London equ ation $\\mathbf{ J } = - \\bar{{ \\rho}}_\\mathbf{s}\\mathbf{ A}$\, wher e $\\mathbf{ J}$ is the current density and $\\mathbf{ A}$ is the vector potential. Using rotor free $\\mathbf{ A}$ and measuring $\\mathbf{ J}$ via the magnetic moment of superconducting rings\, we extract ${\\bar \\rh o _s}$ at $T \\to {T_c}$. The technique\, named Stiffnessometer is sensit ive to very small stiffness\, which translates to penetration depth on th e order of a few millimeters. We apply this method to two different LSCO rings: one with the current running only in the CuO$_2$ planes\, and anoth er where the current must cross planes. We find different transition temp eratures for the two rings\, namely\, there is a temperature range with t wo-dimensional stiffness. The same method is also used to measure the coh erence length $\\xi_0$\, by increasing $A$ to a point where linear respon se break. Finally\, we compare our result with a LEM experiment performed on the same samples and discuss the advantage and disadvantage of each te chnique.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3774/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3774/ END:VEVENT BEGIN:VEVENT SUMMARY:Phase diagram of the perovskite solid solution CaCu$_3$Ti$_{(4-x)} $Ru$_{x}$O$_{12}$ elucidated with bulk $\\mu^+$SR DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3747@indico.stfc.ac.uk DESCRIPTION:Speakers: Elisabetta Nocerino (KTH Royal Institute of Technolo gy)\nThe CaCu$_3$Ti$_{(4-x)}$Ru$_{(x)}$O$_{12}$ family\, synthesized unde r high pressure (7.7 GPa) belongs to the perovskite class of materials. Th e ground state of the extremes of this solid solution are antiferromagneti c insulator for the x = 0 member\, and itinerant-electron system\, i.e.\, Pauli-paramagnetic metal\, for the x = 4 member respectively **[1\,2]**. T he suppression of magnetic ordering from the x = 0 to the x = 4 member of the solid solution seems to be accompanied by non-Fermi liquid (NFL) behav ior since CaCu$_3$Ti$_4$O$_{12}$ manifested indications of such a behavior in heat capacity measurements **[3]**. These features make the solid solu tion CaCu$_3$Ti$_{(4-x)}$Ru$_{(x)}$O$_{12}$ a promising candidate for poss essing a Doniach-type phase diagram **[4]**. In this work we present the r esults of a bulk muon spin rotation study on the intermediate members of t he solid solution\, showing the evolution of the magnetic ground state goi ng from antiferromagnetic to paramagnetic. Evidence of highly dynamical gr ound states are also found among the members of the solid solution and a t entative phase diagram as a function of the Ru content x is proposed.\n\n* *[1]** A. Collomb\, D. Samaras\, B. Bochu\, and J. C. Joubert\, Physica St atus Solidi (a) 41\, 459 (1977)\n**[2]** A. Ramirez\, G. Lawes\, D. Li\, a nd M. Subramanian\, Solid State Communications 131\, 251 (2004)\n**[3]** A . Krimmel\, A. Gunther\, W. Kraetschmer\, H. Dekinger\, N. Buttgen\, A. Lo idl\, S. G. Ebbing-haus\, E.-W. Scheidt\, and W. Scherer\, Phys. Rev. B 78 \, 165126 (2008).\n**[4]** S. Doniach\, Physica B+C 91\, 231 (1977)\n\nhtt ps://indico.stfc.ac.uk/event/53/contributions/3747/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3747/ END:VEVENT BEGIN:VEVENT SUMMARY:Broadband Adiabatic Inversion Cross Polarization (BRAIN-CP) for be ta-NMR DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3794@indico.stfc.ac.uk DESCRIPTION:Speakers: Sydney Kreitzman (TRIUMF)\nCross-polarization techni ques provide a rich playground which allows NMR practitioners a large vari ety of tools to extract detailed spin-hamiltonian parameters of inhomogene ous systems. Beta-detected NMR is almost an ideal arena\, i.e. one spin-po larized 8Li residing in a local structure\, for which to apply such multi- resonant pulse sequences. \nAs such\, an adaptation of NMR's BRAIN-CP R F pulse sequence is described which can in principle extract the dipolar a nd/or quadrupolar spin parameters of the 8Li near neighbours. The polariza tion transfer is achieved in a specifically tuned "double" rotating frame during an adiabatic inversion of the 8Li spin\, and is detected as loss or fine structure in the monitored 8Li z-polarization.\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3794/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3794/ END:VEVENT BEGIN:VEVENT SUMMARY:High-pressure phases of Kitaev materials (as seen by muSR) DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3744@indico.stfc.ac.uk DESCRIPTION:Speakers: Gediminas Simutis (Paul Scherrer Institute)\nBond-de pendent interactions between magnetic moments can lead to strong frustrati on and nontrivial ground states. In particular\, the Kitaev-Heisenberg mod el has a rich phase diagram and can host a spin liquid state or different frozen states depending on the strength of the additional Heisenberg inter actions. Experimentally\, such phase diagrams can be explored by modifying the relative interaction strengths in materials by applying pressure.\n\n In this presentation\, I will describe how the muon spin rotation techniqu e can be used to study such materials under applied pressure and what it c an reveal about the transitions between different phases. I will then show examples of our recent high-pressure studies in Kitaev candidate material s. In Na2IrO3 the magnetic order is enhanced by the application of pressur e up to at least 4 GPa. Combined with structural studies\, we can explain this as a compression of the honeycomb layers [1]. In beta-Li2IrO3\, we fi nd that the magnetically ordered state collapses at 1.4 GPa [2]\, originat ing from dimerization of the Ir ions. In alpha-RuCl3\, a similar phase tra nsition is also observed at about 0.4 GPa [3]\, which is concomitant with unconventional response in the muon polarization function.\n\nI will summa rize the emerging generic picture of Kitaev materials under pressure and w ill discuss the peculiarities of the muon response in these systems.\n\n[1 ] G. Simutis et al.\, PRB **98**\, 104421 (2018)\n[2] M. Majumder et al.\, PRL **120**\, 237202 (2018)\n[3] G. Simutis et al.\, in preparation\n\nht tps://indico.stfc.ac.uk/event/53/contributions/3744/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3744/ END:VEVENT BEGIN:VEVENT SUMMARY:Tunable anomalous Hall conductivity through volume-wise magnetic c ompetition in a topological kagome magnet DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3749@indico.stfc.ac.uk DESCRIPTION:Speakers: Zurab Guguchia (Laboratory for Muon Spin Spectroscop y\, Paul Scherrer Institute\, CH-5232 Villigen PSI\, Switzerland)\nMagneti c topological phases of quantum matter are an emerging frontier in physics and material science. Along these lines\, several kagome magnets have app eared as the most promising platforms. Recently\, we explored magnetic cor relations in the kagome magnet Co$_{3}$Sn$_{2}$S$_{2}$ [1]. Using muon spi n-rotation (${\\mu}$SR) and ARPES\, we present evidence for competing magn etic orders in the topological kagome lattice of this compound. Our result s show that while the sample exhibits an out-of-plane ferromagnetic ground state\, an in-plane antiferromagnetic state appears at temperatures above 90 K\, eventually attaining a volume fraction of 80% around 170 K\, b efore reaching a non-magnetic state. Strikingly\, the reduction of the ano malous Hall conductivity (AHC) above 90 K linearly follows the disappear ance of the volume fraction of the ferromagnetic state. We further show th at the competition of these magnetic phases is tunable through applying ei ther an external magnetic field or hydrostatic pressure. Our results taken together suggest the thermal and quantum tuning of Berry curvature induce d AHC via external tuning of magnetic order. ${\\mu}$SR played a crucial r ole in this study\, since it serves as an extremely sensitive local probe for detecting small moments and ordered magnetic volume fractions in the b ulk of magnetic materials. \n\n[1] Z. Guguchia et. al.\, Nature Communica tions $\\bf{11}$\, 559 (2020).\n\nhttps://indico.stfc.ac.uk/event/53/contr ibutions/3749/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3749/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic ground state of rutile-type oxide RuO$_2$ inferred from m uon DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3750@indico.stfc.ac.uk DESCRIPTION:Speakers: Masatoshi Hiraishi (Ibaraki University)\nRuthenium d ioxide RuO$_2$ is a well-known catalyst applied in various fields due to i ts high electrical conductivity and chemical stability. Although rutile Ru O$_2$ has long been regarded as a Pauli paramagnetic metal\, recent neutro n diffraction experiments and resonant X-ray scattering have suggested the presence of an antiferromagnetic order ($T_\\mathrm{N}>300~$K: Ru moment size $\\sim$0.05$~\\mu_\\mathrm{B}$) associated with the lattice distortio n. This has triggered a growing interest regarding the details of the elec tronic state. We were thus motivated to investigate the magnetic ground st ate of high-quality single crystal RuO$_2$ (residual resistivity ratio RRR >1\,000) by muon spin rotation/relaxation experiment. We found no clear ev idence from $\\mu$SR measurements to suggest the development of a quasi-st atic antiferromagnetic order from $400~$K to $4~$K. The remaining possibil ity is that the muons happen to reside at a site where the internal magnet ic field is canceling. In the presentation\, we will also report the evalu ation of muon site in the rutile structure deduced by first principles cal culations to examine this possibility.\n\nhttps://indico.stfc.ac.uk/event/ 53/contributions/3750/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3750/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muon spin rotation and relaxation study on Li metal DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3785@indico.stfc.ac.uk DESCRIPTION:Speakers: Jun Sugiyama (CROSS Neutron Science and Technology C enter)\nDuring the $\\mu^-$SR measurements on Li-ion battery materials\, a part of implanted $\\mu^-$ is naturally captured by Li nucleus\, leading to the formation of muonic-Li species in target materials. The past $\\mu^ -$SR study on Li metal shows the lack of relaxation in the TF-$\\mu^-$SR s pectrum at room temperature [1]\, despite the presence of large nuclear ma gnetic fields at the muonic-Li position from the surrounding Li nuclei. Su ch phenomenon was explained by diffusion of a He-like muonic-Li in Li meta l. On the other hand\, the He diffusion in solids is reported as a thermal ly activated process based on a thermochronometry gas analysis [2]. Theref ore\, the TF relaxation rate in Li is expected to increase with decreasing temperature\, as the muonic-Li diffusion is suppressed at low temperature s.\nNevertheless\, the $\\mu^-$SR experiment on both natural Li and $^6$Li indicates the absence of detectable TF relaxation rates even at the lowes t temperature measured. This clearly excludes the scenario that the muonic -Li start to diffuse at a certain temperature below 300 K. Although the me chanism on such a zero TF relaxation rate is not fully understood\, we cou ld ignore the contribution from the muonic-Li on the asymmetry $\\mu^-$SR spectrum for the Li-ion battery materials.\n\n[1] D. Favart et al.\, Phys. Rev. Lett. ${\\bf 25}$\, 1348 (1970). \n[2] C. Huber et al.\, Geochimica et Cosmochimica Acta ${\\bf 75}$\, 2170 (2011).\n\nhttps://indico.stfc.ac. uk/event/53/contributions/3785/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3785/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic dopants and spin-density waves: the SmFe$_{1-x}$Mn$_x$AsO case DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3751@indico.stfc.ac.uk DESCRIPTION:Speakers: T. Shiroka (Laboratory for Muon-Spin Spectroscopy\, Paul Scherrer Institut)\nElectronic correlations play a key role in tuning the properties of parent- and doped (superconducting) iron pnictides\, ul timately determining their respective ground states. Parent compounds with magnetic doping are particularly intriguing\, since dopant coupling via R uderman-Kittel-Kasuya-Yosida (RKKY) interactions depends significantly on the strength of electronic correlations\, which interact with the underlyi ng SDW phase. \n\nHere\, we address the interesting case of Fe-to-Mn subst itution in the SmFeAsO parent compound [1] through comparative studies of SmFe$_{1-x}$Mn$_x$AsO\, with $x$(Mn) = 0.05 and 0.10\, via dc-magnetizatio n\, Hall-effect\, and muon‑spin spectroscopy measurements. Our main expe rimental findings are: (i) the Fe-to-Mn substitution weakens the commensur ate spin-density wave (SDW) order of iron\, whose transition temperature d ecreases with increasing Mn content. (ii) At low temperature\, well inside the SDW ordered phase\, an additional magnetic order sets in at $T^*\\sim $ 10 K and 20 K\, for $x$ = 0.05 and 0.10\, respectively. We demonstrate t hat diluted Mn ions can pin the electronic charges and thus induce a radic al reconstruction of the Fermi surface\, in turn responsible for a commens urate-to-incommensurate antiferromagnetic (AF) transition at $T^*$.\n\n\n[ 1] M. Meinero\, P. Bonfà\, I. J. Onuorah\, S. Sanna\, R. De Renzi\, I. Er emin\, M. A. Müller\, J.‑C. Orain\, A. Martinelli\, A. Provino\, P. Man frinetti\, M. Putti\, T. Shiroka and G. Lamura\, *Scientific Reports* **11 **\, 14373 (2021)\, https://doi.org/10.1038/s41598-021-93625-7.\n\nhttps:/ /indico.stfc.ac.uk/event/53/contributions/3751/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3751/ END:VEVENT BEGIN:VEVENT SUMMARY:Status of negative muon at D-Line DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3808@indico.stfc.ac.uk DESCRIPTION:Speakers: Soshi Takeshita (High Energy Accelerator Research Or ganization (KEK))\nThe D-line of the J-PARC MLF MUSE has a pion decay sect ion\, which makes it possible to use decay muons. The superconducting sole noid magnet used in the pion decay section has a large bore and thus produ ce the world's highest positive and negative muon intensities. Since the D -line is currently the only beamline at MUSE where practical negative muon intensity is available\, various user experiments are being conducted usi ng negative muons\, especially in nondestructive elemental analysis\, nega tive muon spin relaxation\, soft errors in semiconductors\, and so on. In addition\, the beamline has been commissioned in various ways including be am tuning to meet the requirements of these experiments. In this talk\, we will report on the recent progress of upgrading at D-line.\n\nhttps://ind ico.stfc.ac.uk/event/53/contributions/3808/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3808/ END:VEVENT BEGIN:VEVENT SUMMARY:The new muSR instrument FLAME at PSI DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3812@indico.stfc.ac.uk DESCRIPTION:Speakers: Hubertus Luetkens (Laboratory for Muon Spin Spectros copy\, Paul Scherrer Institute\, CH-5232 Villigen PSI\, Switzerland )\nHer e\, we report on the status of the setup\, commissioning and first perform ance tests of the newest muSR instrument FLAME (FLexible and Advanced MuSR Environment) at PSI. Commissioning started in spring 2022 after the deliv ery of the superconducting experimental magnet.\n\nFLAME is designed to al low ZF\, LF and TF muSR measurements over a broad temperature range from 2 5mK to 300K with magnetic fields from true zero field up to 3.5T with high spatial homogeneity and temporal stability. \n\nDue to its forward and ba ckward veto system\, it should be possible to study small samples with pra ctically no background. \n\nWe anticipate a time resolution of approximate ly 150ps due to a compact detector design allowing for high TF measurement s with good spectroscopic accuracy and large observable signal amplitude.\ n\nFLAME will have the possibility to mount up to 2 samples (later up to 3 samples) on a ladder holder on the dilution fridge which can successively be brought into the beam at low temperatures. This feature is thought to reduce the ratio between “down” and “up” periods of the instrument \, which is a key factor on a heavily oversubscribed facility as SmuS.\n\n The magnet and muSR spectrometer are designed to be compatible with other cryogenic environments already used at the μSR facility making FLAME a ve ry versatile instrument and ready for future upgrades.\n\nIn addition\, it is foreseen to use FLAME for in-situ modification of samples by external stimuli like uniaxial pressure\, electric fields or electric currents.\n\n By the time of the muSR conference\, we will hopefully be able to present the user community positive results of the commissioning of the instrument and of the first performance tests.\n\nhttps://indico.stfc.ac.uk/event/53 /contributions/3812/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3812/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic Properties of La$_2$CuO$_4$ Nanoparticles DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3755@indico.stfc.ac.uk DESCRIPTION:Speakers: Anita Eka Putri (Meson Science Laboratory\, RIKEN)\n A nano-size effect on magnetic materials shows novel and causes the magnet ic properties different from those observed in a bulk form. The nano-size effect has been well investigated in metals but not yet explored in the hi gh-Tc superconducting oxides. La2CuO4 (LCO) is a parental compound of La-b ased high-T*c* superconducting cuprates which have a long-range antiferrom agnetic (AF) ordering of Cu spins. LCO nanoparticles were synthesized usin g the sol-gel method by controlling the time and temperature of a sinterin g process. It was found from our zero-field μSR on LCO nanoparticles that the magnetic transition temperature drastically decreased with decreasing the particle size. On the other hand\, the saturated internal field at th e muon site did not change at all\, suggesting that the AF spin alignment around the muon in the nanoparticle state is the same as in the bulk sampl e. We proposed a core-shell model to understand our μSR results. We assum ed that the core corresponds to the long-range ordering and a shell corres pond to non-ordered regions where Cu spin did not form a static ordering. We are now investigating how to control oxygen deficiencies that affect ma gnetic interaction in LCO. In our presentation\, detailed μSR results and some characterizations of magnetic properties in LCO nanoparticles will b e reported.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3755/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3755/ END:VEVENT BEGIN:VEVENT SUMMARY:A µSR investigation of the influence of inter-site impurities on quantum spin liquids. DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3742@indico.stfc.ac.uk DESCRIPTION:Speakers: Fabian Hotz (PSI)\nQuantum spin liquids (QSLs) repre sent a state of matter governed by long-range quantum entanglement. These states are stabilized by geometric frustration and remain magnetically dis ordered even at zero temperature. Of particular interest\, are the new exo tic fractional excitations with S = ½\, so-called spinons. Kagome antifer romagnets are known as one of the most promising systems for the realizati on of QSLs\, and the dynamical spin fluctuations are preserved down to the lowest temperatures. On the other hand\, kagome antiferromagnets such as Zn-Brochantite or Zn-Barlowite are polluted by intersite disorder between the copper atoms\, with effective spin ½\, and the nonmagnetic zinc atoms . Therefore\, true observation of QSLs is a formidable task. Nevertheless \, sophisticated techniques such as µSR can unambiguously distinguish the slow fluctuations of QSLs from magnetic order or fast paramagnetic fluctu ations and thus identify possible QSL candidates. More detailed informatio n is also obtained from muon Knight shift measurements\, which directly pr obe the local magnetic susceptibility\, providing information on the gappe d nature of the QSL ground states. Moreover\, the spinon Kondo effect has been observed in a gapless QSL\, in which the magnetic impurities seen by the muons are screened by the surrounding spinons.\n\nhttps://indico.stfc. ac.uk/event/53/contributions/3742/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3742/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic Properties of LiFePO$_4$ under Hydrostatic Pressure DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3756@indico.stfc.ac.uk DESCRIPTION:Speakers: Ugne Miniotaite (KTH Royal Institute of Technology)\ n$\\mathrm{LiFePO}_4$ (LFPO) is an archetypical and well-known cathode mat erial **[1]** for rechargeable Li-ion batteries. However\, its quasi-one-d imensional (Q1D) structure (see Figure) along with the Fe ions\, LFPO also displays interesting low-temperature magnetic properties **[2]**. At ambi ent pressure LFPO display an antiferromagnetic (AFM) spin order below $T_N = 53\\\;\\mathrm{K}$ and neutron scattering **[3-5]** have characterized that LFPO orders in a canted AFM ground state below $T_N$. Our team has pr eviously utilized muon spin rotation ($\\mu^+$SR) to investigate both magn etic order as well as Li-ion diffusion in LFPO **[6]** as well as nano-str uctured LFPO **[7\,8]** and related compounds **[9-11]**. In this initial study we make use of high-pressure $\\mu^+$SR to investigate effects on th e low-T magnetic order. We find a clear decrease in $T_N$ at $p = 20\\\; \ \mathrm{kbar}$ and we can estimate that a complete suppression of magnetic order should appear around $p_c \\approx 300\\\; \\mathrm{kbar}$.\n\n![][ 12]\n [12]: https://neutrons.se/condmat/muSR2022/LFPO_LQ.jpg\n\n**[1]** N ishimura et al.\, Nature Materials 7\, 707-711 (2008)\n**[2]** Santoro\, A cta Crystallogr. 22\, 344 (1967)\n**[3]** Rousse\, et al.\, Chem. Mater. 1 5\, 4082 (2003)\n**[4]** Li\, et al.\, Phys. Rev. B 73\, 024410 (2006)\n** [5]** Toft-Petersen\, et al.\, Phys. Rev. B 92\, 024404 (2015)\n**[6]** Su giyama\, Mansson\, et al.\, Phys. Rev. B 84\, 054430 (2011)\n**[7]** Bened ek\, et al.\, Sustainable Energy & Fuels [RSC] 3\, 508-513 (2019)\n**[8]** Bendek\, et al.\, ACS Applied Materials & Interfaces 12\, 14\, 16243 (202 0)\n**[9]** Ofer\, et al.\, Phys. Proc. 30\, 160 (2012)\n**[10]** Sugiyama \, et al.\, Physical Review Research 2\, 033161 (2020)\n**[11]** Forslund\ , et al.\, arXiv:2111.11941 (2021)\n\nhttps://indico.stfc.ac.uk/event/53/c ontributions/3756/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3756/ END:VEVENT BEGIN:VEVENT SUMMARY:Phase diagram and charge-dynamics of electron-doped osmium based B a$_2$Na$_{1−x}$Ca$_x$OsO$_6$ spin-orbit-coupled Mott insulator DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3757@indico.stfc.ac.uk DESCRIPTION:Speakers: Samuele Sanna (University of Bologna)\nIn recent yea rs\, 5d transition metal oxides have been the focus of increasing research interest\, owing to their rich physics emerging from the interplay betwee n electron correlations and strong spin-orbit coupling (SOC). Such SOC-ind uced insulating phases are frequently accompanied by the transition of the 5d ion to a magnetic state triggered by local structural distortions\, in competition with ground states with exotic multipolar ordering [1].\nOsmi um based double perovskites Ba$_2$Na$_{1−x}$Ca$_x$OsO$_6$ (BNCOO)\, cons titute a remarkable example of SOC-driven physics. In this system\, electr on doping of Os 7+\nby etherovalent substitution of Na by Ca provides a fu rther degree of freedom which strongly affects its magnetic ground state a nd raises TN from a few\nkelvin (x = 0) up to ≈ 40 K (x = 1). 23Na NMR p rovides evidence that the onset of magnetic order is anticipated by local static distortions of the cubic perovskite cell\, breaking the local point symmetry [1].\nHere we report on a combined muSR and NMR experiment which allows us to draw the full phase diagram whith both the local magnetic an d structural symmetry breaking and ordering phases. In addition unambiguou s evidence for the slow diffusion of dynamic lattice distortions in Ca-sub stituted BNCOO at temperatures well above their magnetic transitions is re ported. Their occurrence in conjunction with electron doping support their identification with small polarons [2]\, as predicted by recent theoreti cal studies. We argue that such polarons may play a role as the dynamic pr ecursors of the low-temperature static symmetry-breaking distortions which \, in turn\, seemingly trigger the magnetism in the system.\n\n[1] L. Lu\, et al.\, Nature Communications\, 2017\, 8\, 14407\n[2] C. Franchini\, M. Reticcioli et al. Nature Reviews Materials\, 2021\, 6\, 560\n\nhttps://ind ico.stfc.ac.uk/event/53/contributions/3757/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3757/ END:VEVENT BEGIN:VEVENT SUMMARY:Low temperature spin dynamics in the $S = 2$ kagome magnet Fe$_4$S i$_2$Sn$_7$O$_{16}$: An AC susceptibility\, NMR and µSR study DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3738@indico.stfc.ac.uk DESCRIPTION:Speakers: Rajib Sarkar (TU Dresden)\nFe4Si2Sn7O16 displays an undistorted kagome lattice of Fe2+ (3d6\, S = 2) ions. We present results of DC-pulse-field magnetisation up to 50 T\, Nuclear Magnetic Resonance (N MR)\, AC-susceptibility and muon-spin-resonance (µSR) measurements down t o 19 mK on powder sample of Fe4Si2Sn7O16. The magnetization measurement at 2 K excludes the presence of strong Ising anisotropies. In the temperatur e range of 3 K to 8 K\, the maximum in the real part of AC-susceptibility shows frequency-dependent shift and indicates the presence of spin-glass-l ike behavior. An additional frequency-independent magnetic regime is obser ved below T = 0.7 K. The transverse-field and zero-field µSR results show the onset of static magnetic correlations below 30 K. Further\, below T = 1 K\, ZF-relaxation rate remains relatively constant which indicates the presence of persistence spin dynamics down to 19 mK. Based on the longitud inal field decoupling µSR studies\, we discuss the coexistence of static and dynamic magnetic correlations below 250 mK. From our combined AC-susce ptibility and µSR results\, we demonstrate that in Fe4Si2Sn7O16 the dynam ic magnetic correlations increase below 250 mK and a possible gapless-spin -liquid behavior is achieved.\n\nhttps://indico.stfc.ac.uk/event/53/contri butions/3738/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3738/ END:VEVENT BEGIN:VEVENT SUMMARY:DFT Investigations on Magnetic Properties with Muon in La$_2$CuO$_ 4$ by Using LSDA+U Functional DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3759@indico.stfc.ac.uk DESCRIPTION:Speakers: Supparat Charoenphon (RIKEN)\nThe mother material of the La-based high-Tc superconducting oxides\, La2CuO4(LCO)\, which family of materials possesses a d9 electronic configuration for copper ions\, ac ts as a three-dimensional antiferromagnetic Mott insulator. LCO has been w ell investigated experimentally and theoretically in the past\, but there are still questions on electromagnetic states to be investigated. The on-s ite Coulomb potential\, U\, on the Cu site plays a key role for magnetic p roperties forming the covalent state of electronic orbitals between Cu and O. We are performing first-principles calculations based on the density f unctional theory (DFT) to investigate the covalent state and discuss exper imental results by using muons. One important key issue for this problem i s what kind of electronic correlation functional should be chosen for calc ulations. In our presentation\, we report detail DFT calculation results o n LCO by using the Local Spin Density Approximation (LSDA) functional with the Vienna ab-initio simulation package (VASP) to investigate structural and magnetic properties of LCO. \nThe calculated magnetics moment of Cu in the antiferromagnetically ordered state with the spin direction along the b-axis without the muon is 0.491 μB\, which was agreed upon well with th e neutron scattering experiment. We found that the calculated band structu re and the density of states indicated that U significantly influenced the hybridization of Cu-3d with O-2p orbitals at the valence and conduction b ands influencing the band-gap energy. After adding the muon into the calcu lation model\, it was confirmed that the muon deformed the local crystal s tructure around the preferable muon position and drastically reduced the m agnetic moment of Cu near by the muon changing surrounding electronic stat es. We are now trying to investigate this situation by using other functio nals and will report the results in our presentation.\n\nhttps://indico.st fc.ac.uk/event/53/contributions/3759/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3759/ END:VEVENT BEGIN:VEVENT SUMMARY:Breaking the barriers in understanding your data: Unbiased model s election for muon spin relaxation spectroscopy DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3803@indico.stfc.ac.uk DESCRIPTION:Speakers: Keith Butler (STFC)\nThe analysis of muon spin relax ation experiments typically relies on model fitting under conditions that are ill-posed. Typically models are selected to fit the data based on the inductive bias (physical intuition) of the experimentalist. Although recen t studies have demonstrated the application of unsupervised machine learni ng to automatically detect model changes [https://doi.org/10.1088/1361-648 x/abe39e]\, the use of physical models remains essential for gaining insig hts into the physics and chemistry of the systems under study. This invite s the question - can we use a principled approach\, in concert with the in ductive bias of experienced researchers to select the best models for fitt ing a given data set? In this contribution we demonstrate how Bayesian mod el selection can be applied to select the optimal model from a finite set\ , for fitting data from a given experiment\, avoiding both over- and under -fitting. We use a series of simulated experimental data sets\, with diffe rent underlying models and levels of noise. We show how comparison of Baye s factors\, obtained by integration of Markov Chain Monte Carlo (MCMC) sam pling of the parameter space\, provides robust and principled comparison o f possible models for fitting the data\, and also provides parameter estim ation with associated uncertainties. The latter can be used to determine t he point at which sufficient experimental data have been collected to sati sfactorily assign parameters to the underlying model. Finally\, we also ex plore the application of nested sampling [https://doi.org/10.1063/1.183523 8]\, a method of efficiently sampling posterior distributions\, which coul d allow the extension of this scheme of model selection to higher-dimensio nal models (D>5) while remaining computationally tractable.\n\nhttps://ind ico.stfc.ac.uk/event/53/contributions/3803/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3803/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic structure refinement in the Mott insulator NiS$_2$ DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3761@indico.stfc.ac.uk DESCRIPTION:Speakers: Jonas A. Krieger (Max Planck Institute of Microstruc ture Physics)\nWe present muon spin spectroscopy ($\\mu$SR) measurements o n the antiferromagnetic Mott insulator NiS$_2$. This compound features two subsequent magnetic phase transitions around 38.9K and 29K associated wit h the opening of a Mott gap. From the the rotation dependence of transvers e field $\\mu$SR measurements (Fig. 1b) we confirm the magnetic space grou p 205.33 in the 38.9K to 29K phase\, refined from neutron diffraction $[1] $. Using dipolar field calculations\, we identify a candidate muon stoppin g site on a 24d Wyckoff position (blue site in Fig. 1b inset). We then cal culate the muon stopping sites by using ab-initio density functional theor y (DFT) and relaxing a supercell containing a single muon (i.e. hydrogen) impurity. Indeed the lowest energy muon site is found within 0.2 Angstrom of the experimentally determined one (red site in Fig. 1b inset). In addit ion\, DFT predicts a second stopping site at an 8c Wyckoff position (green site in Fig. 1b inset)\, that can fully explain a small satellite freque ncy that we observe in the spectra. We then use the number of observed fre quencies in the low temperature phase as a constraint to exclude magnetic order parameters inconsistent with our results.\n\n$[1]$ S. Yano\, et al.\ , Phys. Rev. B 93\, 024409 (2016)\n\n![Local field distribution in (a) zer o field and (b) transverse field. The curves are offset for clarity. The i nset shows the candidate muon stopping sites.][1]\n\n\n [1]: https://driv e.google.com/uc?id=10jCaXwniuyysWzkgiKTmvn_yHxz1PfYW\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3761/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3761/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic ground state of YbCo$_2$Zn$_{20}$ probed by muon spin re laxation DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3762@indico.stfc.ac.uk DESCRIPTION:Speakers: Wataru Higemoto (Japan Atomic Energy Agency/Tokyo In stitute of Technology)\nIn intermetallic Ce- and Yb-compounds\, the hybrid ization between the 4$f$ and itinerant conduction electrons induces the ma gnetic instability and charge configurations\, and the ground state prope rties of heavy fermion located in the vicinity of a magnetic quantum criti cal point (QCP) is one of important issue for strongly correlated electron systems. The cubic compound YbCo$_2$Zn$_{20}$ has huge electronic specifi c heat coefficient $\\gamma$=7900mJ/molK$^2$ [2] and its ground state coul d be located in the vicinity of the QCP or a long-range ordered phase. Ind eed\, a magnetic long-range order was observed under pressure above 1-2 GP a[2].\nTo investigate magnetic ground state\, we have carried out muon spi n relaxation measurements and confirm non-magnetic ground state with fluct uating tiny magnetic moment. Detail of the magnetic state will be reported in the presentation.\n\n[1]M. S.Torikachvili\, S.Jia\, E. D.Mun\, S. T.Ha nnahs\, R. C.Black\, W. K.Neils\, D.Martien\, S. L.Bud’ko\, and P. C.Can field\, Proc. Natl. Acad. Sci. U.S.A. 104\, 9960 (2007). \n[2]Y.Saiga\, K. Matsubayashi\, T.Fujiwara\, M.Kosaka\, S.Katano\, M.Hedo\, T.Matsumoto\, a nd Y.Uwatoko\, J. Phys. Soc. Jpn. 77\, 053710 (2008).\n\nhttps://indico.st fc.ac.uk/event/53/contributions/3762/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3762/ END:VEVENT BEGIN:VEVENT SUMMARY:Inverse Laplace Transform Approaches to $\\beta$NMR Relaxation DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3797@indico.stfc.ac.uk DESCRIPTION:Speakers: Andrew MacFarlane (UBC)\, Derek Fujimoto (University of British Columbia)\nSpin lattice relaxation is the simplest type of $\\ beta$NMR measurement. The usual approach is to implant a pulse of hyperpol arized nuclei and monitor the time-resolved $\\beta$-decay asymmetry\, yie lding the ensemble average spin-lattice relaxation. In the simplest case\, the asymmetry decays exponentially with a characteristic time constant $T _1$\, but this ideal is rarely obtained in practice. In most data\, the re laxation is more complicated. This can be the result of multiple crystallo graphic sites for the implanted probe each having a distinct $T_1$. The sa mple may also be inhomogeneous due to: impurities or defects (including in terfaces important for thin films)\; intrinsic phase separation\; or\, if it is a glass. There may also be a background signal from probe ions that stop outside the sample. The general approach to this problem has been the *ad hoc* development of an appropriate relaxation model that avoids overp arametrization.\n\nGiven the prevalence of more complicated relaxation\, i t is crucial to develop a *systematic* approach to relaxation modelling. T he decomposition of a relaxing signal into exponentials is\, however\, a m athematically ill-posed problem$^1$. This feature is intrinsic and unavoid able\, but there are a number of methods to accommodate it for noisy real- world data\, including nuclear spin relaxation$^2$\n\nHere we demonstrate regularization methods for the inverse Laplace transform adapted to the pa rticularities of $\\beta$NMR relaxation data\, most importantly the strong time dependence of the statistical uncertainty stemming from the radioact ive lifetime of the probe.\n\n$^1$ see Istratrov et al\, Rev. Sci. Instr.7 0\, 1233 (1999)\n$^2$ Spencer et al\, NMR in Biomedicine 33\, e4315 (2020) \; Singer et al\, PRB 101\, 174508 (2020).\n\nhttps://indico.stfc.ac.uk/ev ent/53/contributions/3797/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3797/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigating magnetic skyrmion in Pt/CoFeB/Ru multilayers with lo w-energy MuSR DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3763@indico.stfc.ac.uk DESCRIPTION:Speakers: Yasmine Sassa (Department of Physics\, Chalmers Univ ersity of Technology\, 41296 Göteborg\, Sweden)\nAfter the first observat ion of magnetic skyrmion in 2009\, the so-called skyrmionics research fiel d is still rapidly evolving. To this day\, intense research effort is stil l carrying on in understanding their intrinsic properties for the potentia l realization of future energy efficient nanodevices. Magnetic skyrmion in thin multilayer films are appealing because their emergence\, stability\, and physical properties can be engineered by controlling dipolar\, perpen dicular anisotropy and Dzyaloshinskii−Moriya (DM) interactions at interf aces through the choice of materials\, layer thickness\, and film stacks. Among numerous multilayers systems\, Pt/CoFeB/Ru is an excellent platform to study the skyrmion phase\, but also other magnetic fluctuations that ma y arise from competing orders. In addition to the DMI at the Pt/CoFeB inte rface\, in thick multilayers\, dipolar interactions favorize the formation of the Néel-type chiral domain walls close to the edges of the multilaye r\, and results in the creation of skyrmions with hybrid chirality.\nHere\ , we present a low-energy muon spin rotation study on Pt/CoFeB/Ru multilay ers as function of temperature and magnetic field. From both transverse fi eld (TF) and longitudinal fields (LF) measurements\, a clear magnetic tran sition between T= 475-500 K is observed\, with fluctuations appearing at T ≤ 550 K. Interestingly\, the relaxing components for the LF measuremen ts show a change of fractions and depolarization rates as function of temp erature\, but not as a function of magnetic field. Our results suggest the presence of domain wall dynamics in these systems\, which are independent of the skyrmion phase.\n\nhttps://indico.stfc.ac.uk/event/53/contribution s/3763/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3763/ END:VEVENT BEGIN:VEVENT SUMMARY:A MaxEnt-μSR study: Precursor effects of the Fe3O4 Verwey transi tion DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3764@indico.stfc.ac.uk DESCRIPTION:Speakers: Carolus Boekema (San Jose State University)\nUsing m uon-spin rotation (μSR) [1] the magnetic fields of Fe3O4 have been previo usly investigated. The Verwey transition at Tv (~123 K) and a transition at Tw (~247 K) are observed. Using Maximum-Entropy (MaxEnt) μSR data of single-crystal Fe3O4 are analyzed with much improved precision. [2\,3] We review earlier results [3] and report on our analysis of the temperature dependence of fields with B (720 Oe) // . Below the demagnetization field \, extra μSR signals are found at Bext // indicating two frequencies at room temperature (RT) and two at 205 K. [3] At RT\, the upper frequency f ollows the zero-field trend seen in the Tv-Tw region of the zero-field (ZF ) phase diagram. At 205 K\, the lower frequency follows the extension of the ZF trend above Tw. These two ZF trends indicate plausible short-range ordering related to the “extra” 3d-electron conduction behavior. Thi s should further be interpreted as precursor effects to the Tv transition. [1] Our MaxEnt-μSR finding is consistent with diffuse [4] & x-ray [5] s cattering results above Tv providing a clear picture of the magnetic envir onments in Fe3O4. This new interpretation indicates two T-dependent magne tizations\, reflecting different short-range orders [3-5] in the ZF phase diagram of this Mott-Wigner glass.[6]\nResearch supported by LANL-DOE\, SJ SU & AFC San Jose.\n[1] C. Boekema et al\, Phys Rev B33 (1986) 2102\; Ph ys Rev B31 (1985) 1233 & references therein. \n[2] C Boekema and MC Browne \, MaxEnt 2008\, AIP Conf Proc #1073 (2008) 260. \n[3] C Morante and C Boe kema\, AIP Advances 10 (2020).025005. \n[4] A Bosak et al\, Phys Rev X4 (2 014) 011040. \n[5] G Perversi et al\, Nature Comm 10 (2019).2857. \n[6] JH VJ Brabers et al\, J Physics Condensed Matter 12 (2000) 5437.\n\nhttps://i ndico.stfc.ac.uk/event/53/contributions/3764/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3764/ END:VEVENT BEGIN:VEVENT SUMMARY:Metal State with Spontaneously Broken Time-Reversal Symmetry above the Superconducting Phase Transition DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3777@indico.stfc.ac.uk DESCRIPTION:Speakers: Hans-Henning Klauss (TU Dresden)\nFundamentally\, wh at distinguishes a superconducting state from a normal state is a spontane ously broken symmetry corresponding to the long-range coherence of Cooper pairs\, leading to zero resistivity and diamagnetism. \nHere we report a s et of thermodynamic\, transport and muon spectroscopy observations on a se ries of hole-doped Ba$_{1−x}$K$_x$Fe$_2$As$_2$. Our specific-heat measur ements indicate the formation of fermionic bound states when the temperatu re is lowered from the normal state. However\, at the doping level $x$  ≈ 0.8\, instead of the characteristic onset of diamagnetic screening a nd zero resistance expected below a superconducting phase transition (T$_c $)\, we observe the opposite effect: the generation of self-induced magnet ic fields in the resistive state\, measured by spontaneous Nernst effect [ 1] and muon spin rotation experiments [2\,3] (see Fig.1). This combined ev idence indicates the existence of a bosonic metal state in the temperature range T$_c$ ≤ T ≤ T$_{Z2}$ in which Cooper pairs of electrons lack co herence\, but the system spontaneously breaks time-reversal symmetry (Z2). The observations are consistent with the theory of a state with fermionic quadrupling\, in which long-range order exists not between Cooper pairs b ut only between *pairs of pairs*.\n\n![(Top panel) Temperature dependence of the zero-field muon spin relaxation rate (left) and the magnetic suscep tibility measured in B∥ab = 0.5 mT (right) for the stack of single c rystals with x = 0.78(3) [3]. (Bottom panel) Temperature dependence of the spontaneous Nernst effect (left) and the magnetic susceptibility measur ed in B∥ab = 0.5 mT (right) for a sample with x = 0.77. The comp arison suggests that the origin of the spontaneous Nernst effect at T$_{Z2 }$ is the appearance of spontaneous magnetic fields.][1]\n\n$[$1$]$ V. Gri nenko et al.\, Nat. Phys. 17\, 1254–1259 (2021). \n$[$2$]$ V. Grinenko e t al.\, Phys. Rev. B 95\, 214511 (2017).\n$[$3$]$ V. Grinenko et al.\, Nat . Phys. 16\, 789–794 (2020).\n\n\n [1]: https://www.dropbox.com/s/c2v8w 43fggvy5pe/BKFA.jpg?dl=0\n\nhttps://indico.stfc.ac.uk/event/53/contributio ns/3777/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3777/ END:VEVENT BEGIN:VEVENT SUMMARY:Evolution of the magnitude of the exchange and Dzyaloshinskii-Mori ya interactions under pressure in chiral magnet MnSi DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3765@indico.stfc.ac.uk DESCRIPTION:Speakers: Pierre Dalmas de Reotier (Univ. Grenoble Alpes)\nThe intermetallic compound MnSi exhibits a number of properties that have att racted strong interest. In particular it magnetically orders below 29.5 K to an exotic long-pitch helical structure. This type of order is due to th e presence of the Dzyaloshinskii-Moriya interaction\, authorized by the ab sence of inversion symmetry in the crystal structure\, that coexists with a dominant ferromagnetic exchange interaction.\nAs often observed in stron gly correlated magnets\, the properties of MnSi are strongly influenced by the application of a relatively modest pressure. The MnSi ordering temper ature decreases with pressure up to ~1.5 GPa\, above which value its groun d state is non-magnetic.\nHere we report on recent zero-field $\\mu$SR mea surements aimed at determining the evolution of the magnetic order under p ressure. Up to 1.3 GPa\, the high statistics asymmetry spectra can be anal ysed using the model derived a couple of years ago for the interpretation of room pressure measurements [1]. Thanks to a prior determination of the muon site and of the muon coupling parameters\, the parameters entering th e model are directly those of the magnetic structure.\nFor each pressure\, we find the ordered magnetic moment $m$ to decrease as $T^2$ from its low temperature value\, similar to earlier results obtained at room pressure [2]. This decrease is the signature of the excitations of spin waves (heli magnons) as the temperature is raised. The quadratic temperature dependenc e reflects the form and anisotropy of the helimagnon dispersion relation. From the slope of $m(T)$ vs $T^2$ we determine the two parameters of the d ispersion relation\, from which we quantitatively deduce the magnitude of the exchange and Dzyaloshinskii-Moriya interactions at each pressure. Fina lly the spectra recorded at 1.44 GPa are discussed.\n[1] P. Dalmas de Reot ier et al\, Phys. Rev. B 93\, 144419 (2016).\n[2] A. Yaouanc et al\, Phys. Rev. Research 2\, 013029 (2020).\n\nhttps://indico.stfc.ac.uk/event/53/co ntributions/3765/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3765/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigation of the magnetic topological insulator family (MnBi$_ 2$Te$_4$) (Bi$_2$Te$_3$)$_n$ by μSR and NMR DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3766@indico.stfc.ac.uk DESCRIPTION:Speakers: Manaswini Sahoo (IFW \,Dresden\, Germany\, Dipartime nto di Scienze Matematiche\, Fisiche ed Informatiche\, Universit`a di Parm a\, Parco Area delle Scienze 7A\, I-43100 Parma\, Italy)\n[[Fig. 1 ($MnBi_ 2Te_4$) ($Bi_2Te_3$)n Zero Field μSR asymmetries vs. time at different te mperatures][Fig1]\nTime-reversal symmetry breaking in a topological insula tor (TI) opens a surface gap and distinguishes chiral quantum states that could eventually be exploited in electrically controlled spintronic device s. The new approach to this state in a TI is with the intrinsic magnetic p roximity of a magnetic insulator that can be achieved with layered van der Waals materials.\n($MnBi_2Te_4$) ($Bi_2Te_3$)n are one of the first such examples\, where the increasing number n of TI layers controls the magneti c properties and dimensionality of the material. These compounds do displa y the quantum anomalous Hall effect\, a hallmark of a magnetic TI\, where spontaneous magnetization and spin-orbit coupling lead to a topologically non-trivial electronic structure. Magnetic order critical temperatures det ected by macroscopic magnetization are $T_N$=25\,13K for n=0\,1 and $T_C$= 12K for n=2 with a lower metamagnetic transition at $T_M$=6K for n=1[1\,2\ ,3].\nZero-field μSR (see Fig. 1) shows more than one internal field at t he muon site with the majority one decreasing in value when n is increased . The muon spin precessions display very fast relaxations of static inhomo geneous nature\, and the longitudinal asymmetry component displays critica l slowing down of fluctuations at $T_C$. Remarkably the high field site di sappears above $T_M$. NMR additionally shows the presence of a small anti- site component (likely Mn in the Bi site) in the n=1 sample. This local in formation is crucial to correctly interpret macroscopic magnetization data .\n\n\n[1] M. M. Otrokov et. al\, Nature 576\, 416 (2019)\n[2] Raphael C. Vidal et.al\, Physical Review X 9\, 041065 (2019)\n[3] M. Z. Shi et.al\, P hysical Review B 100\, 155144 (2019)\n\n\n\n [Fig1]: https://univpr-my.sh arepoint.com/:i:/g/personal/roberto_derenzi_unipr_it/EZS-WVKEoelBjkzuh855A BsBebMS9rrZm6tBLaw_S-MXQA?e=bxZIoN\n\nhttps://indico.stfc.ac.uk/event/53/c ontributions/3766/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3766/ END:VEVENT BEGIN:VEVENT SUMMARY:Hydrogen diffusion observed in photoinduced YO$_1$H$_2$ thin films DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3727@indico.stfc.ac.uk DESCRIPTION:Speakers: Yuya Komatsu (Tokyo Tech)\nMaterials showing high ph otoresponsive electrical resistance have attracted considerable attention due to their photoelectronic applications.[1] Recently\, we have reported that yttrium oxyhydride (YO$_x$H$_y$) epitaxial thin films exhibit a repea table photo-induced insulator-to-metal transition by UV laser illumination and thermal relaxation.[2] The photo-induced metallization likely origina tes from the carrier generation reaction: H$^−$ + $h$$\\nu$ → H$^+$ + 2e$^−$\, which generates excess electrons and protons.[2\,3] This sugges ts that a local environmental change around hydrogen in the epitaxial YO$_ x$H$_y$ thin film plays an important role in the photo-induced metallizati on process. To further understand the hydrogen dynamics in the YO$_x$H$_y$ epitaxial thin film\, here\, we used $^8$Li $\\beta$-NMR for pristine and UV-illuminated thin films. For the as-fabricated sample\, the spin-lattic e relaxation rate (1/T$_1$) is constant as ~0.2 s$^-$$^1$ in the temperatu re range between 100 to 300 K. For the UV-illuminated sample\, the tempera ture-independent 1/T1 of ~0.3 s$^-$$^1$ is also observed at temperatures b elow 200 K\, indicating an increase in 1/T$_1$ by UV illumination. There a re two possible origins for the increase in 1/T$_1$: one is the generation of color centers and the other is the enhancement of the interaction betw een dilute paramagnetic moments and photocarriers. Furthermore\, we found that 1/T$_1$ increases with increasing temperature only for the UV-illumin ated sample at temperatures above 200 K\; this implies a change in the nuc lear magnetic field due to hydrogen dynamics. These results suggest that t he hydrogen dynamics are thermally activated and a change of the local env ironment around hydrogen under UV illumination.\n\nReferences:\n[1] Li et al.\, Phys. Status Solidi B 249\, 1861 (2012).\n[2] Komatsu et al.\, Chem. Mater. 34\, 3616 (2022).\n[3] Hayashi et al.\, Nature 419\, 462 (2002).\n \nhttps://indico.stfc.ac.uk/event/53/contributions/3727/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3727/ END:VEVENT BEGIN:VEVENT SUMMARY:A muon-spin relaxation study of type-I rhenium investigating time- reversal symmetry breaking in the superconducting state DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3768@indico.stfc.ac.uk DESCRIPTION:Speakers: David Jonas (University of Warwick)\nTime-reversal s ymmetry breaking is a signature of unconventional superconductivity and ca n be observed from zero-field muon spin relaxation measurements as an incr ease of the muon relaxation rate through the superconducting transition te mperature. Time-reversal symmetry breaking\, although rare\, has been obse rved in several noncentrosymmetric rhenium-based intermetallic superconduc tors [1].\n\nRecent results indicate that elemental rhenium powder\, exhib iting type-II superconductivity with a transition temperature of 2.7 K\, a lso breaks time-reversal symmetry [2]. This suggests that the local electr onic structure of rhenium may be intrinsically linked to the unconventiona l superconductivity in the rhenium-based materials. However\, removing int ernal strain from the rhenium by melting or annealing reduces the transiti on temperature to 1.7 K and leads to type-I superconductivity.\n\nIn the p resent study\, we have investigated the superconductivity in type-I rheniu m using zero-field muon-spin relaxation measurements [3]. No unconventiona l behaviour is observed\, and time-reversal symmetry is preserved in the s uperconducting state. Instead of the muons remaining stationary over their lifetime\, we observe muon diffusion across the full temperature range st udied\, with muons quantum-mechanically hopping between interstitial sites . The hopping rate exhibits metallic behaviour in the normal state. In the superconducting state\, the behaviour can be described qualitatively by i ncluding the presence of the superconducting energy gap and energy asymmet ries between muon sites from crystallographic defects.\n\nThese results ca ll into question the role the electronic structure of rhenium plays in the breaking of time-reversal symmetry in rhenium-based intermetallic superco nductors and demonstrates that the behaviour of muon spectroscopy data can be governed by muon diffusion effects.\n\n[1] S. K. Ghosh\, *et al.*\, J. Phys. Condens. Matter **33**\, 033001 (2020).\n[2] T. Shang\, *et al.*\, Phys. Rev. Lett. **121**\, 257002 (2018).\n[3] D. G. C. Jonas *et al.*\, P hys. Rev. B **105**\, L020503 (2022).\n\nhttps://indico.stfc.ac.uk/event/5 3/contributions/3768/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3768/ END:VEVENT BEGIN:VEVENT SUMMARY:LE-muSR Study of the Meissner state. New Results on an Old Proble m. DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3769@indico.stfc.ac.uk DESCRIPTION:Speakers: Vladimir Kozhevnikov ()\nThe Meissner state (MS) is the state with the most pronounced superconducting properties. Therefore\, knowledge and understanding properties of the MS is a necessary condition to understand and predict properties of all other states of all supercond uctors. The standard interpretation of the MS is based on the theory of F. and H. London\, with minor modifications adopted in the Ginzburg-Landau a nd Bardeen-Cooper-Schrieffer theories. Londons’ theory rests on three po stulates: (i) the magnetic permeability $\\mu$ and dielectric permittivity $\\varepsilon$ are equal to unity\; (ii) the induction $B$ and\, conseque ntly\, the intensity $H(=B/\\mu)$ of the magnetic field is zero\; and (iii ) the penetration depth $\\lambda$ is independent of the applied field $H_ 0$. Quite long-ago\, using thermodynamic considerations\, H. London showed that $\\lambda$ must depend on $H_0$. The first application of Pippard's microwave resonator technique was to verify this statement. Pippard found a weak increase of $\\lambda$ vs $H_0$ nonmonotonically changing with temp erature\, and concluded that $\\lambda$ can be viewed as independent of $H _0$. This result was (and still is) regarded as a confirmation of the Lon don theory (F. London\, 1950). However\, the standard diagram of the Abrik osov vortices suggests that $\\lambda$ strongly decreases with the field. Soon after Pippard’s experiment\, Shoenberg noted that Londons’ theory conflicts with the law of energy conservation. Besides\, Londons’ postu late $\\mu=\\varepsilon=1$ implies that the electromagnetic properties of superconductors are identical to those of vacuum. To sort out with these and other fundamental issues in the MS interpretation\, we launched the LE -$\\mu$SR project aimed at measuring the field dependence of the induction profile near the surface of high-quality type-I and type-II superconducto rs in the MS. The entire profile (from $B=H_0$ to zero) was measured for the first time. The results obtained to date and the challenges we are enc ountering in this investigation will be reported.\n\nhttps://indico.stfc.a c.uk/event/53/contributions/3769/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3769/ END:VEVENT BEGIN:VEVENT SUMMARY:LE-muSR Study of the Field Distribution and the Domain Shape near the Surface of Superconductors in the Intermediate State* DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3770@indico.stfc.ac.uk DESCRIPTION:Speakers: vladimir kozhevnikov ()\nAs known (Landau\, 1937)\, the equilibrium domain structure of the magnetic flux in type-I supercondu ctors in the intermediate state is formed due to the competition between t he energy contributions to the sample free energy arising from the superco nducting/normal interfaces\, on one side\, and the contributions due to an inhomogeneous field distribution and the domains shape (FDDS) near the sa mple surface\, on the other. Landau suggested two scenarios for FDDS\, oth er scenarios were proposed by Tinkham\, Marchenko and Abrikosov. However\, none of these scenarios meets the fundamentals of the Laplace-based magne tostatics being simultaneously consistent with observed flux structure. We will report on for the first time performed direct measurements of the FD DS near the surface of planar samples in the intermedium state\, i.e.\, on high purity indium films in a normally applied field. The measurements we re carried out using LE-$\\mu$SR. The range of the probed distances from t he surface extends from 0.1 $\\mu$m inside to 1 $\\mu$m outside the sample . It was found that\, contrarily to what follows from the Laplace equation \, the current-free space outside the samples contains voids extending ove r a large-scale distance\, which can exceed the thickness of the samples. More specifically\, at low fields the measured FDDS is close to that sugge sted by Tinkham. However\, at high fields the real FDDS differs from all p redictions: the width of the superconducting domains widens instead of exp ected narrowing and outside the samples the field passes through a maximum \, in apparent violation of Earnshaw’s theorem. It will be shown that th e observed FDDS is thermodynamically the most favorable for the supercondu cting sample\, which leads to inapplicability of the Laplace equation and\ , consequently\, the Earnshaw theorem in a wide vicinity of the sample in the intermediate state. \n\n*V. Kozhevnikov et al.\, J Supercond Nov Magn 33\, 3361 (2020).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/377 0/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3770/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic nature of wolframite MnReO$_4$ DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3752@indico.stfc.ac.uk DESCRIPTION:Speakers: Elisabetta Nocerino (KTH Royal Institute of Technolo gy)\nRhenium oxide compounds of the type AReO$_4$ where A is a first-row t ransition metal cation\, exhibit interesting electronic properties. Among this family of compounds\, MnReO$_4$ was the first of this kind\, synthesi zed with a high-pressure technique at 25 kbar in 1970 **[1]**. It has a wo lframite structure where both cations have partially filled d shells\, and an anisotropic electrical resistivity that makes it suitable for potentia l applications in the development of electrical devices **[2]**. Although this material was already known for several years\, the magnetic propertie s of MnReO$_4$ have never been studied in detail. In this work we present the very first investigation of the magnetic nature of the wolframite insu lator MnReO$_4$ carried out by muon spin rotation. The aim of the experime nt was to clarify the occurrence a static antiferromagnetic order\, and th e possibility for the formation of magnetic multipole order at low tempera tures\, which is expected due to the lack of an inversion symmetry at the Re6+ site and a strong spin-orbital coupling of its 5d1 electron. The occu rrence of the static antiferromagnetic ordering was clearly observed in Mn ReO$_4$ and the order parameter of the transition was determined.\n\n**[1] ** A. W. Sleight\, Inorg. Chem. 14\, 597 (1975).\n**[2]** A. W. Sleight\, United States Patent\, 4027004 (1977).\n\nhttps://indico.stfc.ac.uk/event/ 53/contributions/3752/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3752/ END:VEVENT BEGIN:VEVENT SUMMARY:Enhancement of strong coupling s-wave superconductivity in the vic inity of a quantum critical point in (Ca\,Sr)$_3$Rh$_4$Sn$_{13}$ DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3771@indico.stfc.ac.uk DESCRIPTION:Speakers: Jonas A. Krieger (Max Planck Institute of Microstruc ture Physics)\nWe report muon spin rotation ($\\mu$SR) studies of the supe rconducting properties as a function of chemical and hydrostatic pressure on the cubic ternary intermetallic (Ca$_{x}$Sr$_{1-x}$)$_{3}$Rh$_{4}$Sn$_{ 13}$ compounds\, which feature strong coupling phonon-mediated BCS superco nductivity and a structural phase transition a critical pressure p$_c$ ass ociated with a charge density wave (CDW) formation$\\\,[1]$. A strong enha ncement of the superfluid density and a pronounced maximum in the pairing strength provide evidence of a quantum critial point at p$_c$\, which sepa rates a superconducting phase coexisting with CDW from a pure superconduct ing phase. In both phases superconductivity has a phonon-mediated BCS $s$- wave character. Together with the related isoelectronic compound Ca$_{3}$I r$_{4}$Sn$_{13}$ $[2]$\, this system shows that conventional BCS supercond uctors in the presence of competing orders may display behavior and charac teristics of unconventional superconductors.\n\n$[1]$ S. K. Goh\, et al.\, Phys. Rev. Lett. 114\, 097002 (2015)\n$[2]$ P. K. Biswas\, et al.\, Phys. Rev. B 92\, 195122 (2015)\n\n![(a) Depolarization rate and center field a s a function of temperature at ambient pressure for different chemical com positions. (b) Superconducting state parameters as a function of combined chemical and hydrostatic pressure.][1]\n\n [1]:https://drive.google.com/u c?id=1F3Lzv57gR69OI7FELh3q3IPZs0C6Pxep\n\nhttps://indico.stfc.ac.uk/event/ 53/contributions/3771/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3771/ END:VEVENT BEGIN:VEVENT SUMMARY:Superconductivity in TiSe$_2$ Under Hydrostatic Pressure DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3773@indico.stfc.ac.uk DESCRIPTION:Speakers: Frank Elson (KTH\, Royal Institute of Technology)\nO ne of the key challenges in the condensed matter research field is underst anding the pairing mechanisms that give rise to unconventional superconduc tivity. Transition metal dichalcogenides $MX_2$ ($M$ = Nb\, Ti\, Ta\, Mo a nd $X$ = S\, Se) are a class of materials that have been shown to exhibit competition between a charge density wave (CDW) and superconducting state [ 1]. In ambient conditions\, TiSe$_2$ displays a CDW state in ambient con ditions and has also been shown to undergo a superconducting transition wh en intercalated with Cu [2] and when hydrostatic pressure is applied [3]. Here\, we have conducted a muon spin resonance (µ+SR) experiment on a pow der sample of TiSe$_2$ under hydrostatic pressure. The measurements were c onducted at the GPD beamline\, Paul Scherrer Institute. Measurements were taken at high pressure (22.9 kbar) and at zero pressure in order to compar e\, and at two muon momentums of 100 MeV/c and 95 MeV/c. All these measure ments were taken in field cooled conditions under 100 Gauss. We can say th at the response from the lower momentum muons is mainly from the pressure cell\, and the larger momentum muons respond more to the sample. We see a possible two s-wave gap behaviour for the high-pressure results\, fixing T $_C$ = 1.8K\, Δ$_1$ = 1.03meV and Δ$_2$ = 0.096 meV where Δ is the maxi mum value of the gap for each contribution. Results from other µ+SR studi es using copper doped TiSe$_2$ show a similar behaviour [4]\, suggesting t hese mechanisms are similar. Further analysis on these results shall allow us to put this material on an Uemura plot.\n[ 1]J.Wilson\,et al\, Adv.In Phys.24.2\,117(1975)\n[2]A.D.Hillier et al\, Phys.Rev.B 81\, p.092507 (201 0)\n[3]Kusmartseva\, et al. Phys.Rev letters\, 103(23)\, p.236401 (2009)\n [4]M.Zaberchik et al. Phys.Rev.B 81\, p.220505(R) (2010)\n\n![Temperature dependence of the relaxation rate from TiSe$_2$ under pressure.][1]\n\n\n [1]: https://drive.google.com/uc?id=1DuoyTM0tYiMOYPqhl-HMw1jF_WwAq5Bu\n\n https://indico.stfc.ac.uk/event/53/contributions/3773/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3773/ END:VEVENT BEGIN:VEVENT SUMMARY:Superconductivity nearby quantum critical point in hole-doped orga nic strange metal $\\kappa$-(ET)$_{4}$Hg$_{3-\\delta}$Br$_{8}$ DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3776@indico.stfc.ac.uk DESCRIPTION:Speakers: Dita Puspita Sari (College of Engineering\, Shibaura Institute of Technology)\nThe hole-doped organic superconductor $\\kappa$ -(ET)$_{4}$Hg$_{3-\\delta}$Br$_{8}$\, ($\\kappa$-HgBr)\, where $\\delta$=1 1% and \nET=bis(ethylenedithio)tetrathiafulvalene\, has been the key to br idge the knowledge gap between half-filled organics and doped cuprate syst ems. Nonetheless\, the isotropic triangular lattice of ET dimers of $\\kap pa$-HgBr\, unlike the square lattice in cuprates\, is suspected responsibl e for its susceptibility which is well scaled with the organic spin liquid insulator $\\kappa$-(ET)$_{2}$Cu$_{2}$(CN)$_{3}$. However\, both $\\kappa $-HgBr and cuprate have a region at high temperature and high-pressure cor responding to the $strange$ $metallic$ state where resistivity exhibits a linear temperature dependence which is non-Fermi-liquid (non-FL) behavior. In $\\kappa$-HgBr this non-FL region gradually changed to an FL state by pressure [1]\, like the change of metallic state from optimal to overdoped cuprates. The $^{13}$C-NMR concluded that the antiferromagnetic fluctuati ons contribute to the origin of the non-FL in $\\kappa$-HgBr [3]. This evi dence may locate superconducting $\\kappa$-HgBr nearby quantum critical po int (QCP) in between FL and localized states\, where in its non-FL state t he incoherent conductivity was observed [1\,3].\n\nOur zero-field $\\mu^+$ SR experiment showed the relaxation rate from around 10 K down to 0.3 K is temperature-independent. This is a high possibility of the superconductin g state that preserved time-reversal symmetry. There was almost no change in the 120 Oe of transverse-field-$\\mu^{+}$SR time spectra\, at 0.3 K and above the superconducting temperature $T_{c}$ = 4.6 K\, indicating that t he London penetration depth is longer than a $\\mu$m order\, while we esti mate the lower critical field\, $H_{c1} = 25(5)$ Oe. These could be an ind ication of a strong-coupling superconductor. We will discuss a possible me chanism of preserved time-reversal Cooper pairing formation from strong-co upling non-FL metal with geometrical frustration.\n\n[1] H. Taniguchi\, et al.\, J. Phys. Soc. Jpn. 11\, 113709 (2007)\n[2] Y. Eto\, et al.\, Phys. Rev. B 81\, 212503 (2010)\n[3] H. Oike\, et al.\, Nat. Commun. 8\, 756 (20 17)\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3776/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3776/ END:VEVENT BEGIN:VEVENT SUMMARY:Online learning to train users of muons and neutrons at ISIS DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3807@indico.stfc.ac.uk DESCRIPTION:Speakers: Peter Baker (STFC)\nOnline learning is being adopted across a wide range of disciplines as remote access to resources\, wideni ng participation in training\, and an appreciation of the diverse approach es of learners have come to prominence. Online resources can also be used to augment more traditional in-person training by bringing a cohort of lea rners up to a common minimum level beforehand\, distributing materials dur ing the course\, and reinforcing learning after the event.\n\nOver the las t six years ISIS has developed online learning materials about muon and ne utron science that sit alongside other neutron science materials produced as part of the SINE 2020 project. The materials include lecture videos\, q uizzes\, and introductions to science areas\, experimental techniques\, an d computational methods. These have been used by hundreds of students\, th ose participating in training schools\, those preparing for experiments or data analysis\, and those with another interest in these subjects. Users have provided consistently positive feedback on the available content. Fol lowing the conclusion of the SINE2020 project\, the materials are now host ed by the PaNOSC and ExPaNDS projects at: [https://e-learning.pan-training .eu/][1]. \n\nWe will describe the materials now available\, the opportuni ties and challenges of online training for facility users\, and the develo pments planned for coming years.\n\n [1]: https://e-learning.pan-training .eu/\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3807/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3807/ END:VEVENT BEGIN:VEVENT SUMMARY:In situ\, operando investigation of thin film devices using LE-μS R DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3813@indico.stfc.ac.uk DESCRIPTION:Speakers: Zaher Salman (Paul Scherrer Institute)\nTuning the e nergy of incoming muons in the low energy muons (LEM) spectrometer is done primarily by applying a high voltage (HV) on the sample plate to accelera te or decelerate the implanted muons. Therefore\, any manipulation on the sample that requires the use of direct contacts to it becomes complicated. For example\, in order to run a current through the sample or apply an el ectric field on the sample\, the power supply and contacts have to be on t he same HV as the sample. A simple way to achieve this is to place the pow er supply (or any other standard lab equipment or device) on an insulated platform outside the cryostat and bias both the sample and the device by t he same HV. Although the idea is simple\, its application requires serious safety and reliability considerations. Here we present the design of this HV table (see figure) and discuss some applications in various thin film devices.\n![Schematic of the LEM high voltage table][1]\n\n\n [1]: https: //drive.switch.ch/index.php/s/EGlFIpTaDp28wvd/download\n\nhttps://indico.s tfc.ac.uk/event/53/contributions/3813/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3813/ END:VEVENT BEGIN:VEVENT SUMMARY:Ubiquitous Spin Freezing in Spin-Triplet Superconductor UTe$_2$ DTSTART;VALUE=DATE-TIME:20220829T132000Z DTEND;VALUE=DATE-TIME:20220829T134000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3775@indico.stfc.ac.uk DESCRIPTION:Speakers: Jeff Sonier (Department of Physics\, Simon Fraser Un iversity)\nThe novel superconductor UTe$_2$ is a rare material wherein ele ctrons form Cooper pairs in a unique spin-triplet state with potential top ological properties. Theoretically\, spin-triplet superconductivity in UTe $_2$ may be explained in terms of pairing mediated by either ferromagnetic or antiferromagnetic fluctuations\, but experimentally the magnetic prope rties of UTe$_2$ remain enigmatic. Here we report on a $\\mu$SR study of i ndependently grown UTe$_2$ single crystals that exhibit either a single or double phase transition in the specific heat near the onset of supercondu ctivity. In the absence of an applied magnetic field\, we observe an inhom ogeneous distribution of magnetic fields in a sizeable volume fraction of all samples studied. The growth in the volume of the magnetic regions is h alted by the onset of superconductivity at the critical temperature $T_c$. Upon further cooling\, slow fluctuations of the local fields persist unti l a disordered spin frozen state appears below about one tenth of $T_c$. T he $\\mu$SR results are consistent with the formation of magnetic clusters in UTe$_2$ due to the influence of disorder on long-range electronic corr elations or geometrical magnetic frustration associated with the ladder-li ke U sublattice structure. Our findings suggest that inhomogeneous magneti c clusters are responsible for the ubiquitous residual linear term and low -temperature upturn in the temperature dependence of the specific heat in UTe$_2$ below $T_c$. The omnipresent magnetic inhomogeneity may also have implications for the interpretation of other low-temperature experimental observations in the superconducting state of UTe$_2$.\n\nhttps://indico.st fc.ac.uk/event/53/contributions/3775/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3775/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muon spin rotation and relaxation on superconducting MgB$ _2$ DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3778@indico.stfc.ac.uk DESCRIPTION:Speakers: Jun Sugiyama (CROSS Neutron Science and Technology C enter)\nAlthough $\\mu^+$SR is widely used as a tool for studying a micros copic internal magnetic field in condensed matters over 40 years\, the cou nterpart technique\, i.e.\, $\\mu^-$SR is less common for such purpose mai nly due to a low counting rate for reaching reliable statistics. However\, the recent progress in the beam power and counting system overcame such p roblem. We therefore started a new $\\mu^-$SR project to measure a nuclear magnetic field in hydrogen storage materials and battery materials since 2018 [1]. \nIn order to expand the $\\mu^-$SR work\, we have attempted to measure the $\\mu^-$SR spectra on superconducting MgB$_2$ in ISIS to join the time reversal symmetry breaking business. This is because the past $\\ mu^+$SR work on MgB$_2$ [2] reported the dynamic change in a nuclear magne tic field even below $T_c=39$ K due to muon diffusion\, resulting in diffi culty to know the variation of the nuclear magnetic field below $T_c$. Fro m a $\\mu^-$SR viewpoint\, Mg almost lacks nuclear magnetic moments (since the natural abundance of $^{25}$Mg with $I=5/2$ is 10%)\, and as a result \, the $\\mu^-$s captured by Mg feel a nuclear magnetic field formed by su rrounding B and could detect the change in it accompanied with the superco nducting transition. Note that the natural abundance of $^{10}$B with $I=3 $ is 19.9% and that of $^{11}$B with $I=3/2$ is 80.1%. Thus\, the $\\mu^-$ captured by B should exhibits a fast decay due to its own nuclear magneti c moment\, and the corresponding asymmetry will disappear. \n\n[1] J. Sugi yama et al.\, Phys. Rev. Lett. ${\\bf121}$\, 087202 (2018).\n[2] Ch. Niede rmayer et al.\, Phys. Rev. B ${\\bf65}$\, 094512 (2002).\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3778/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3778/ END:VEVENT BEGIN:VEVENT SUMMARY:Mott-insulating state of alkali-metal clusters in sodalite studied by $\\mu$SR DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3754@indico.stfc.ac.uk DESCRIPTION:Speakers: Takehito Nakano (Ibaraki University)\nIn Mott insula tors\, band electrons are localized due to strong electron-electron intera ctions. Although the s-electrons of alkali metals are very delocalized\, b y confining them in the periodic nanospace of zeolite crystals and making them moderately localized\, such a strongly correlated electron system can be created.$^1$ In sodalite\, $\\beta$-cages with an inner diameter of 0. 7 nm are arranged in a bcc structure. By loading alkali atoms\, an $A_4^{3 +}$ cluster ($A$: alkali atom) is formed in the cage. The cluster has one unpaired s-electron. Antiferromagnetic order of Mott insulating state has been identified in $A =$ Na\, K\, and K-Rb alloy clusters.$^2$ $T_N$ syste matically increases from 50 K (Na) to 90 K (K-Rb alloy). In ZF-$\\mu^+$SR\ , a uniform local field is observed below $T_N$\, and its value is higher for clusters with heavier chemical compositions.$^2$\nTo clarify the mecha nism of the systematic change in the local field and its relation with the Mott-insulating state of this system\, we investigate the muon Knight shi ft by high TF-$\\mu^+$SR using NuTime at TRIUMF. We successfully obtained the hyperfine coupling constants between $\\mu^+$ and the s-electron above $T_N$ from the $K-\\chi$ plot. By combining the ZF-$\\mu^+$SR local field \,$^2$ we determined the size of the ordered moments\, which systematicall y decreases from $\\simeq$ 0.5 $\\mu_B$ (Na) to $\\simeq$ 0.3 $\\mu_B$ (K- Rb alloy). It correlates perfectly with the increase in $T_N$\, namely\, t he decrease in the electron correlation $U/t$ in the Mott-Hubbard model. F rom DFT calculations\, we found that $\\mu^+$ is in a hydride (Mu−) stat e at the cage center. This also explains that the systematic increase in t he local field corresponds to the decrease in $U/t$ due to the shallower p otential of the heavier alkali atoms.\n$^1$T. Nakano and Y. Nozue\, Adv. P hys.: X **2**\, 254-280 (2017). \n$^2$T. Nakano *et al*.\, J. Phys. Soc. J pn. **79**\, 073707-1-4 (2010).\n\nhttps://indico.stfc.ac.uk/event/53/cont ributions/3754/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3754/ END:VEVENT BEGIN:VEVENT SUMMARY:The mechanism of superconductivity in the controversial spinel oxi de LiTi$_2$O$_4$ clarified with LE$\\mu^+$SR DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3779@indico.stfc.ac.uk DESCRIPTION:Speakers: Elisabetta Nocerino (KTH Royal Institute of Technolo gy)\nThe very first low-energy muon spin rotation (LE-$\\mu^+$SR) study pe rformed on LiTi$_2$O$_4$ films in the Meissner state is presented. LiTi$_2 $O$_4$ is a unique spinel type superconductor in which the mechanism under lying superconductivity is highly debated **[1]**. LE-$\\mu^+$SR is a dire ct probe for the characterization of depth dependent properties in thin fi lms\, which allowed us to extract the London penetration depth ($\\lambda_ {\\rm L}=241\\pm15$~nm) and the temperature dependence of the superconduct ing order parameter for LiTi$_2$O$_4$\, among other relevant quantities. T he order parameter was found to not follow any of the standard models with in the realm of the mean field theory. In particular\, the value of the cr itical exponent\, close to 1\, suggests that the superconductivity in LiTi $_2$O$_4$ is of unconventional nature. Indeed\, by plotting the correlatio n between the critical temperature Tc and the London penetration depth for LiTi$_2$O$_4$ in Uemura’s scaling relation for doped cuprates\, we see that its behavior is close to the one of electron doped cuprates. We concl uded that the observed behavior is compatible with a superconductivity of BCS type\, with disturbance by Ti3+ spin fluctuations\, which introduce a time reversal symmetry breaking perturbation in the system. This measureme nt gives a robust indication that LTO is a nonconventional SC and sets an important step forward in understanding the controversial nature of superc onductivity in this material.\n\n**[1]** E. G. Moshopoulou\, J. Am. Ceram. Soc.\, 82 [12] 3317–20 (1999)\n\nhttps://indico.stfc.ac.uk/event/53/con tributions/3779/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3779/ END:VEVENT BEGIN:VEVENT SUMMARY:Reinventing the Muon Decay Channel DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3781@indico.stfc.ac.uk DESCRIPTION:Speakers: Sydney Kreitzman (TRIUMF)\nThis work describes the n ew M9H muon decay channel at TRIUMF\, which is specifically designed to de liver high quality transversely spin polarized beams. Transverse polarizat ions in both X and Y of ~80% over the momentum range 70-120MeV/c are expec ted. In contrast to a traditional z-polarized decay beam the key to accom plishing this task lies in the extraction an off-centre momentum-canted di stribution of muons exiting the decay solenoid. We describe both the theor etical and practical considerations that have informed the design.\n\nhttp s://indico.stfc.ac.uk/event/53/contributions/3781/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3781/ END:VEVENT BEGIN:VEVENT SUMMARY:Tracking Decay Positrons in a Magnetic Field for Muon Microscope A pplications DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3789@indico.stfc.ac.uk DESCRIPTION:Speakers: Kenji Kojima (Centre for Molecular and Materials Sci ence\, TRIUMF and Stewart Blusson Quantum Matter Institute\, the Universit y of British Columbia)\nWe present a theoretical calculation for feasibili ty study of the Muon Microscope\, which is intended to add positional reso lutions within the sample by tracking down the positron trajectories to it s source positions. In the presence of a magnetic field\, any positrons wh ose trajectories have components which are perpendicular to the magnetic f ield will start to move in a helical path due to the Lorentz force. Taking special relativity into account\, we have analytically determined the tra jectories of the positrons in a uniform magnetic field. This solution serv es as a guiding principle before going to a more realistic case\, such as the distribution of the magnetic fields and positron scattering from the c ryostat walls. \n\nFor the first step of the G4beamline simulation\, we pl aced three virtual detectors (meaning they do not interact with the positr ons) in the up stream direction at $z$=100\, 150 and 200 mm from the sampl e respectively. When we apply a uniform magnetic field of 0.3 Tesla in th e $z$-direction\, the helical tracking analysis reproduces the source posi tion with the accuracy of 0.3 mm in Full Width Half Maximum (FWHM). It is considerably more accurate than the quadratic interpolation method (FWHM=2 .4 mm) as shown in Fig. 1.\n![Comparison of the tracked back position for the positron sources at (0\,0) in the helical approximation and quadratic approximation][1]\nInclusion of the positron scattering from the cryostat wall and the inhomogeneity of the magnetic field will reduce the spatial r esolution\, and we will discuss them quantitatively from our G4simulation results from the realistic settings.\n\nCY is grateful for the Erich Vogt First Year Student Research Experience (FYSRE) award from Department of Ph ysics and Astronomy\, the University of British Columbia.\n\n\n [1]: http s://cmms.triumf.ca/~kojima/musr2022/HelicalVSQuad.jpg\n\nhttps://indico.st fc.ac.uk/event/53/contributions/3789/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3789/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of a stable measurement system for Radio-Frequency stu dies of muonium reactivity with metal nanoparticles and surface-adsorbed m olecules in mesoporous hosts DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3786@indico.stfc.ac.uk DESCRIPTION:Speakers: Stephen Cottrell (STFC)\nWe have recently begun an i nvestigation of paramagnetic (free-radical) final states formed on metal n anoparticles by muonium reactivity with surface-adsorbed molecules. The na noparticles are incorporated into mesoporous silica\, facilitating specifi c reaction steps in the silica host that involve H-atom transfer reactions important to studies in heterogeneous catalysis. Radio-frequency (RF) met hods are an essential tool for characterising final state species in these systems\, and a non-metallic sample cell is essential for running these m easurements to ensure the RF field penetrates the sample. Initial measurem ents were carried out using an existing cell with a body made from PEEK po lymer\, using a 1/16” capillary to enable vapour to be introduced into t he cell in-situ. Unfortunately\, several significant problems were encount ered during initial experiments\, the most serious being a temporal instab ility in the signals measured for both pure silica and for systems loaded with small pressures of benzene. This paper reports in detail on the probl ems encountered using the PEEK cell\, and then discusses the development o f a more reliable experimental setup giving better reproducibility for the se measurements. The new sample cell has been fabricated from Shapal\, a c eramic material with good thermal properties. Previous experience of using Shapal components in gas RF cells has suggested this is a ‘clean’ mat erial that gives none of the outgassing issues previously associated with PEEK. While rebuilding the cell\, the opportunity was also taken to improv e the conductance of the vapour transfer tube. The success of the new cell is demonstrated both through off-line tests and by muon measurements\, in cluding a series of TF 2G muonium spin precession measurements designed to verify the temporal stability of the experimental setup. Finally\, an RF cavity was fashioned\, and RF measurements made for muons stopped in bare silica\, with signals from both diamagnetic and paramagnetic muon states c learly seen.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3786/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3786/ END:VEVENT BEGIN:VEVENT SUMMARY:Integration of arts and sciences by using negative muon non-destru ctive analysis at J-PARC MUSE DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3791@indico.stfc.ac.uk DESCRIPTION:Speakers: Yasuhiro Miyake (KEK)\nWe have been developing a non -destructive\, position-selective\, and quantitative multi-elemental analy sis method by using negative muons at J-PARC MUSE. Our final goal is to es tablish a platform of the integration of arts and science\, where historic al relics can be analyzed non-destructively\, by combining quantum beams t echniques utilizing muons\, neutron or photons.\nAt the symposium\, the cu rrent status of the negative muon non-destructive analysis held at J-PARC MUSE\, on Japanese old coins (Koban\, Cho-gin)\, bell‐shaped bronze vess el of the Yayoi period\, and Ogata Koan's sealed medicine etc. will be int roduced.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3791/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3791/ END:VEVENT BEGIN:VEVENT SUMMARY:BEAMS: A New User-Friendly Program for Analyzing μSR Data DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3788@indico.stfc.ac.uk DESCRIPTION:Speakers: Alec Petersen (Brigham Young University)\nTo support the continued growth of μSR\, it is important to encourage prospective n ew users by minimizing any barriers to entry to the μSR community. As wit h any other scientific approach\, one such barrier to entry can be the sof tware tools necessary to extract useful information from the data. Althoug h excellent software options for μSR currently exist\, in our experience\ , students and other new μSR practitioners often struggle to learn how to use these tools. For this reason\, we have developed BEAMS\, a comprehens ive\, user-friendly computer program for μSR data analysis designed to co mplement existing μSR programs as an accessible entry point into μSR dat a analysis. BEAMS is an open-source\, python-based graphical program that enables interactive inspection of μSR data and flexible fitting of mathem atical functions to asymmetry spectra through non-linear least-squares opt imization. The program currently accepts data from TRIUMF\, PSI\, and ISIS . The software is available for Windows\, Mac\, and Linux operating system s through a simple installation procedure. The source code\, helpful tutor ial videos\, and detailed documentation are available at https://github.co m/FrandsenGroup/beams to help new users take advantage of BEAMS as an easy -to-use tool for analyzing μSR data.\n\nhttps://indico.stfc.ac.uk/event/5 3/contributions/3788/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3788/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of Transient µSR at J-PARC DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3792@indico.stfc.ac.uk DESCRIPTION:Speakers: Shoichiro Nishimura (KEK IMSS)\nTo obtain one time-d ifferential $\\mu$SR spectrum using a conventional technique\, we must wai t around $10^2$ minutes. In the majority of $\\mu$SR experiments\, the $\\ mu$SR spectrum is recorded as a function of temperature. Thus\, such a lon g recording time ($t_{record}$) has not been a serious problem\, because t he lead time ($t_{read}$) for stabilizing temperature requires typically 1 0-20 min\, which is shorter than the recording time ($t_{lead}\n\nhttps:// indico.stfc.ac.uk/event/53/contributions/3792/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3792/ END:VEVENT BEGIN:VEVENT SUMMARY:Precise measurement of the hyperfine splitting in muonium with a h igh intensity pulsed muon beam at J-PARC DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3793@indico.stfc.ac.uk DESCRIPTION:Speakers: Ryoto Iwai (KEK)\nA muonium is a purely leptonic bou nd system of a positive muon and an electron.\nFundamental properties of s uch a system can be precisely predicted by the QED\, whereas ordinal atoms require to calculate hadronic interactions.\n\nAt J-PARC\, the MuSEUM (Mu onium Spectroscopy Experiment Using Microwave) collaboration aims to preci sely measure the ground-state hyperfine splitting of muonium atoms\, arisi ng from spins of the muon and electron.\nThe pulsed muon beam is stopped i n a krypton gas cell to form the muonium atoms.\nThe transitions of spin s tates are induced with a microwave cavity\, which is then measured by posi tron counters. \n\nIn previously performed measurement with a nearly-zero magnetic field [1\,2]\, the resonance of the hyperfine transition was succ essfully observed with a relative precision of 160 ppb.\nAs a next step\, we plan to perform the measurements with strong magnetic fields\, so that the different frequency shifts by Zeeman splitting allow us to more precis ely determine the transition rate down to 1.2 ppb.\nThis unprecedented pre cision will be achieved by upgrading several components of the experimenta l setup\, including a new high intensity muon beamline which is currently commissioned at J-PARC.\nPerforming measurements at various magnetic field strengths requires to replace the current cylindrical microwave cavity wi th a new boxed-shaped cavity.\n\nIn this presentation\, the general scheme of our experiment and status of the upgrades for the new measurement are reported.\n\n[1] S. Kanda et al.\, Phys. Lett. B 815\, 136154 (2021).\n[2] S. Nishimura et al.\, Phys. Rev. A 104\, L020801 (2021).\n\nhttps://indic o.stfc.ac.uk/event/53/contributions/3793/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3793/ END:VEVENT BEGIN:VEVENT SUMMARY:Using the TCDFT method to determine muon quantum effects DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3834@indico.stfc.ac.uk DESCRIPTION:Speakers: Yue Yuan (STFC/University of Science and Technology of China)\nIn calculations supporting μSR\, it is important to deal with muon quantum effects. In previous studies\, people have gone beyond the po int-like muon approximation by using methods such as vibrational analysis of the zero point motion and path-integral molecular dynamics.[1-3] We now use a new method called Two-component DFT (TCDFT)\, which treats the muon as a fully quantized particle with its own wave-function.[4]\nBy modifyin g the Quantum Espresso DFT code[5]\, we have included the potential genera ted by a muon trial wave-function into the DFT calculation of electronic s tructure and optimum geometry. Once we have the crystal and electron struc tures\, the new muon wave-function can be calculated by solving its Schrö dinger equation via a finite difference method. Repeating iteratively the two-component calculation\, we could get a self-consistent result for both the electron and muon wave-functions. \nDue to many-body quantum effects\ , we need to use the Quantum Monte Carlo method to simulate the correlatio n energy and pair-correlation function. The former is used for the TCDFT c alculation and the latter is used for coupling the individual wave-functio ns of the muon and electrons when calculating a specified physical quantit y. In this work\, we have already applied the new method to some ferromagn etic systems (Fe\, Co\, Ni) and the calculations are now being extended to some examples of semiconductors (Diamond\, Si\, Ge) and single molecules (TCNQ and acetone). From the results obtained so far\, we have calculated muon hyperfine contact fields\, which agree well with experiments and sho w good potential for further application of the method to other materials. \n[1] I. Onuorah et al\, PHYSICAL REVIEW MATERIALS. 3\, 073804(2019)\n[2] J. Möller et al\, PHYSICAL REVIEW B. 87\, 121108(R)(2013) \n[3] M. Gomil šek et al\, arXiv:2202.05859(2022)\n[4] J. Wiktor et al\, PHYSICAL REVIEW B. 92\, 125113(2015)\n[5] P. Giannozzi et al.\, J. Phys.:Condens. Matter 21 395502(2009)\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3834/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3834/ END:VEVENT BEGIN:VEVENT SUMMARY:$^{8}$Li Spin Relaxation as a Probe of the Modification of Molecul ar Dynamics by Inelastic Deformation of Glassy Polystyrene DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3799@indico.stfc.ac.uk DESCRIPTION:Speakers: Derek Fujimoto (University of British Columbia)\, W. Andrew MacFarlane (UBC)\nGlasses occupy more volume than required for mol ecular close packing. The distribution of this ``free volume'' is related to other key properties such as dynamic heterogeneity (stretched exponenti al relaxation). As a glass ages\, it equilibrates by thermally activated s tructural relaxation producing permanent densification with slowed relaxat ion times. Mechanical deformation can significantly alter glassy structure and relaxation\, leading to apparent over-aging or rejuvenation via irrev ersible plastic shear flow that explores microscopic configurations that a re otherwise inaccessible$^1$.\n\nNanoimprint$^2$ is a technique that defo rms thin polymer films by indentation of a patterned die for lithographic patterning and measuring mechanical properties. Few techniques are capable of studying local properties of polymer films\, however the spin-lattice relaxation of implanted $^8$Li$^+$ is sensitive to the molecular dynamics in the glassy state\, including modification by processing parameters$^3$\ n\nWe report initial results on a 300 nm thick atactic polystyrene film pl astically modified by nanoimprint stamping$^4$ using a 1 mm ultra-smooth s pherical die. While the \\elip\\ beam can easily be stopped in the film\, the beamspot is $\\sim 2$ mm in diameter\, so a large array of imprints wa s produced over an area $\\sim 3$ mm$^2$\, leaving an inelastic strain of a few tenths of a percent over an areal fraction $\\sim 20$%.\n\nTo ensure the beam overlapped the imprinted area\, a new method was developed. Usin g scintillation from an Al$_2$O$_3$ crystal\, the beamspot image was fit w ith a Gaussian profile. Partially automation allowed the overlap to be max imized in real time. We find a small but significant change in the bulk of the film (away from the surface)\, compared to an unimprinted control\, t he relaxation is slower and more inhomogeneous (lower stretching exponent) .\n\n$^1$ McKenna\, JPCM**15**\, S737 (2003)\n$^2$ Traub\, Ann.Rev.Chem.Bi o.Eng. **7**\, 583 (2016).\n$^3$ McKenzie\, SoftMatter**14**\, 7324 (2018) .\n$^4$ Cross\, Rev.Sci.Inst.**79**\, 013904 (2008).\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3799/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3799/ END:VEVENT BEGIN:VEVENT SUMMARY:Muonium 1S-2S spectroscopy with improved statistics DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3833@indico.stfc.ac.uk DESCRIPTION:Speakers: Shinsuke Yamamoto ()\nOur purpose is precision measu rement of the 1S-2S energy interval in Muonium\, which is an exotic hydrog en-like atom consists of a positive muon and an electron. This purely lept onic system enables a precise calculation of the energy interval with the Standard Model without any concerns of the uncertainty from the charge rad ius of the nucleus\, unlike the hydrogenatom. This advantage motivates us to measure the precise 1S-2S energy interval in Muonium with technology of laser spectroscopy and to determine the muon mass with the highest accura cy of 10 ppb. The improvement of muon mass accuracy has an impact on verif ication of the Standard Model\, muon g-2/EDM experiment\, for example. In addition\, our technique of Muonium laser ionization is related to muon ac celerator or muon microscope.\n\nThe energy interval accuracy has been sta tistically limited since 1999[1]. However\, more powerful muon beam is ava ilable now at J-PARC in Japan and we are developing new UV laser system. \ n\nWe will report a recent result of Muonium 1S-2S energy interval measure ment at J-PARC. The event rate in our experiment is 50 times higher than t he previous experiment. This dramatic improvement gives promising prospect for higher accuracy of 1S-2S energy interval and the muon mass accuracy i n the future. \n[1]V. Meyer et al\, Phys. Rev. Lett 84\, 1136(2000)\n\nhtt ps://indico.stfc.ac.uk/event/53/contributions/3833/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3833/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muon spin rotation and relaxation study on antiferromagne tic order of Na clusters in sodalite DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3804@indico.stfc.ac.uk DESCRIPTION:Speakers: Takehito Nakano (Ibaraki University)\n$\\mu^+$SR is used in various research fields as a sensitive local magnetic probe. Altho ugh the implanted $\\mu^+$ stop at interstitial sites in the crystal\, it is often difficult to determine the sites precisely. On the other hand\, t he implanted $\\mu^-$ are captured by nuclei and have different lifetimes for each nuclide. Thus\, the $\\mu^-$ position is unambiguously determined by measuring the lifetime. However\, the spin polarization of $\\mu^-$ is reduced down to about 1/6 during the capture process\, requiring much hig her statistics than $\\mu^+$SR. Recent improvements in the beam intensity and detection efficiency of pulsed-muon facilities have made $\\mu^-$SR ex periments feasible\, and such an advanced $\\mu^-$SR is used to study ion dynamics in solids.$^1$ We here report an attempt to investigate magnetic materials with the advanced $\\mu^-$SR.\nNa$_4^{3+}$ clusters can be arran ged in a bcc structure in sodalite crystal. Antiferromagnetic ordering occ urs below $T_N =$ 50 K due to the exchange interaction between the s-elect rons in the arrayed clusters. In ZF-$\\mu^+$SR\, a homogeneous local field of 92 Oe is observed at low temperatures.$^2$ Our recent study shows it ’s due to the Fermi contact at the cage center. In the present $\\mu^-$S R\, the lifetime analysis shows the signal at the oxygen site is dominant. The initial asymmetry of the time spectra dropped sharply below $T_N$\, b ut muon spin precession due to a homogeneous local field couldn’t be obs erved. The decoupling by longitudinal field shows the local field of about 0.4 kOe. This value can be explained as the local field of oxygen sites w hen the spatial distribution of s-electron wave function is approximately incorporated. These results demonstrate the importance to study the magnet ic nature of materials with $\\mu^{\\pm}$SR.\n$^1$I. Umegaki *et al*.\, J. Phys. Chem. C **126**\, 10506 (2022).\n$^2$R. Scheuermann *et al*.\, Phys . Rev. B **66**\, 144429 (2002).\n\nhttps://indico.stfc.ac.uk/event/53/con tributions/3804/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3804/ END:VEVENT BEGIN:VEVENT SUMMARY:Thermal desorption spectrometry system for complementary hydrogen measurements of $\\mu$SR experiments DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3827@indico.stfc.ac.uk DESCRIPTION:Speakers: Ryosuke Kadono (KEK IMSS)\nMuon probing hydrogen stu dy is based on the fact that the target material contains at least a small amount of hydrogen. Therefore\, a high-sensitivity measurement of hydroge n abundance would be useful as a complementary measurement of $\\mu$SR exp eriments. We are developing a high-sensitivity thermal desorption spectrom etry (TDS) system to perform such complementary measurements.\nTDS is know n as a method to evaluate the hydrogen abundance in a material$^1$. The pr inciple is that a sample is heated in an ultra-high vacuum\, the partial p ressure of the released gas is measured with a quadrupole mass spectromete r\, and the gas abundance is quantitatively evaluated by integrating the s pectrum. Recently\, the development of a TDS system that detects hydrogen with a high sensitivity of 10$^{16}$ atoms cm$^{-3}$\, the highly hydrogen sensitive TDS (HHS-TDS) system\, was reported$^{2\,3}$. Our system is a m odified version of this HHS-TDS system suitable for complementary measurem ents of $\\mu$SR experiments.\nWhile a conventional TDS system consists of a stainless steel UHV chamber\, the HHS-TDS system consists of a chamber made of Be-Cu alloy. This alloy\, which has a precise composition of Be$_{ 0.2}$Ni$_2$Ag$_{0.1}$Zr$_{0.2}$Cu$_{97.5}$\, is suitable as a chamber mate rial because of its good thermal conductivity\, low hydrogen solubility\, and hardness to form a vacuum flange$^4$. In our system\, the sample geome try was designed to allow measurement of thin-film substrates mounted on a flag-style sample holder\, which is to make the measurement compatible wi th experiments using ultra-slow muons. We will report on the commissioning of the vacuum chamber and the infrared laser of the TDS system.\n\n![Snap shot of commissioning status of TDS system][1]\n\n1) J. B. Taylor and I. L angmuir\, Phys. Rev. 44\, 423 (1933).\n2) T. Hanna et al.\, Rev. Sci. Inst rum. 88\, 053103 (2017).\n3) K. Iwaya et al.\, Materials research meeting 2021\, E5-O1-02\, Yokohama\, Japan\, 2021.\n4) https://www.toel.co.jp/\n\n [1]: https://cdn.amebaowndme.com/madrid-prd/madrid-web/images/sites/1767 806/341889892f7d0c18b2b0702e4dcdff31_5868af10b881f75ace672a978f4aac2e.jpg\ n\nhttps://indico.stfc.ac.uk/event/53/contributions/3827/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3827/ END:VEVENT BEGIN:VEVENT SUMMARY:Depth profiling of LE-$\\mu$SR parameters with musrfit DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3826@indico.stfc.ac.uk DESCRIPTION:Speakers: Maria Mendes Martins (Laboratory for Muon Spin Spect roscopy\, Paul Scherrer Institute)\nThe study of thin-film and multi-layer ed structures with nanometer resolution is possible with low energy $\\mu$ SR (LE-$\\mu$SR). The average stopping depth of the positive muons with im planted energies between 1 and 25 keV extends over a few nanometers and de pends on the density of the probed material. \nModeling of the measured $\ \mu$SR parameters such as diamagnetic asymmetry and relaxation rate as a f unction of sample depth can be obtained from a series of experimental impl antation energy measurements and its correlation with the simulated stoppi ng profiles. The fitting approach assumes a sharp transition between regio ns with distinct properties\, such as layers with different materials\, de fects\, and intermixing near the interface\, or\, depletion regions where the charge carriers concentrations may change. The fitting method\, previo usly developed in matlab\, is being implemented in musrfit\, a free $\\mu$ SR data analysis framework written in C++. The main goal is to make this f itting method widely available for energy dependent measurements and incre ase the modeling possibilities within musrfit.\nWe will present the added functionality\, its implementation\, and different examples where the syst ems measured with LE-$\\mu$SR could be better understood by quantifying th e width of physically relevant regions.\n\nhttps://indico.stfc.ac.uk/event /53/contributions/3826/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3826/ END:VEVENT BEGIN:VEVENT SUMMARY:Present status of J-PARC MUSE DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3811@indico.stfc.ac.uk DESCRIPTION:Speakers: Koichiro Shimomura (KEK/J-PARC)\nJ-PARC MUSE is resp onsible for the inter-university user program and the operation\, maintena nce\, and construction of the muon beamlines\, namely D-line\, S-line\, U- line\, and H-line\, along with the muon source at MLF. \nAt D-line\, which provides the world’s most intense pulsed negative and positive muon bea ms\, various scientific studies\, including those on industrial applicatio ns\, archeology\, and fundamental physics\, have been performed. In FY2021 \, non-destructive analysis was carried out on samples brought back by Hay abusa2 from the asteroid Ryugu\, which are thought to preserve the element al composition of the solar system in its primordial state. \nStable opera tions have been achieved in S1 area of S-line for μSR. In addition\, a gr oup at Okayama University constructed a new experimental area\, S2\, in FY 2020 for muonium 1s-2s measurement. \nU-line\, uses electrostatic lenses t o focus low-energy muons obtained by laser ionization of thermal muonium t o produce energy-variable and high time-resolution ultra-slow pulsed muon beams for various experiments. A muon spin spectrometer for materials scie nce research using the μSR method has been installed in the U1A area\, an d is being upgraded and upgraded for the start of the inter-university use r program. The spectrometer is located on a high-voltage stage and the dep th of penetration into the sample can be controlled in the range from sub- keV to 30 keV.\nThe H line is a high-intensity muon beamline where experim ents such as high-statistics fundamental physics experiments and transmiss ion muon microscopy are planned. The first beam observed in the H1 experim ental area\, the first branch\, in January 2022.\nAt present\, the beam co mmissioning is being carried out in collaboration with several research gr oups that plan to conduct experiments at the H-line.\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3811/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3811/ END:VEVENT BEGIN:VEVENT SUMMARY:$^8$Li $\\beta$NMR studies of Epitaxial Thin Films of the 3D topol ogical Dirac semimetal Sr$_3$SnO DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3728@indico.stfc.ac.uk DESCRIPTION:Speakers: Andrew MacFarlane (UBC)\nThe inverse perovskite Sr$_ 3$SnO is a 3D cubic Dirac semimetal with a very small energy gap\, a so-ca lled topological crystalline insulator$^1$. The unusual electronic structu re confers a variety of novel properties\, such as chiral topological surf ace states\, and very strong itinerant electron orbital magnetism. Remarka bly\, when doped it also becomes superconducting$^2$. In the most insulati ng samples\, the Fermi level lies close to the Dirac points\, and orbital magnetism is maximal. We report the results of ion-implanted $^8$Li$^+$ $\ \beta$NMR in Au capped epitaxial thin films of Sr$_3$SnO as a function of carrier content which can be finely tuned by the growth conditions. In add ition\, we stop the $^8$Li in the Au overlayer to seek proximal evidence o f the chiral surface state. \n\nIn high magnetic field (6.55 T)\, we find remarkably little contrast in spin-lattice relaxation between low carrier density Sr$_3$SnO and the Au overlayer. In the insulator\, $1/T_1 \\sim 0. 14$ s$^{-1}$ is slightly faster than Au at 300 K\, while\, in the overlaye r\, there is a small but systematic enhancement in $1/T_1$. The resonance in the insulator is broad with a long tail towards negative shift without resolved quadrupolar splitting.\n\n$^1$A.W. Rost et al.\, APL Materials 7\ , 121114 (2019).\n$^2$M. Oudah et al.\, Nat. Comm. 7 (2016) 10.1038/ncomms 13617.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3728/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3728/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic surface state on pure and iron-doped palladium thin films DTSTART;VALUE=DATE-TIME:20220901T160000Z DTEND;VALUE=DATE-TIME:20220901T162000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3712@indico.stfc.ac.uk DESCRIPTION:Speakers: Thomas Prokscha (PSI)\nElemental palladium (Pd) is a well-known paramagnetic transition metal. Doping with iron impurities lea ds to giant magnetic moment formation and spin glass behavior. Pd surfaces often show different behavior than bulk Pd [1\,2]\, which is particularly relevant in research fields working with Pd nanomaterial\, such as for ex ample catalysis and spintronics. \nWe present depth-dependent transversal field µSR measurements with low-energy muons (1 keV-25 keV) on 100 nm Pd thin films at temperatures of 3.7-200 K and external magnetic fields of 10 -330 mT. These measurements reveal a magnetic surface state both on pure e lemental Pd and on iron-doped (170 ppm) Pd samples. The surface state is c haracterized by an increased muon field and increased muon depolarization rate at the sample surface and at the interface with the silicon substrate . The interior of all thin films shows bulk-like Pd properties\, in accord ance with earlier bulk-µSR measurements [3]. The surface is different fro m the bulk for all samples\, in one case\, we even found a strong indicati on for a paramagnetic to ferromagnetic phase transition at the surface. We argue that orbital moments induced at the surface / interface by localize d spins and charges are the most likely origin of the observed surface sta te [4]. \n[1] T. J. N. Hooper et al.\, Phys. Chem. Chemical Physics 20\, 2 6734 (2018).\n[2] W. A. MacFarlane et al.\, Phys. Rev. B 88\, 144424 (2013 ).\n[3] K. Nagamine et al.\, Phys. Rev. Lett. 38\, 99 (1977).\n[4] A. Hern ando et al.\, Phys. Rev. B 74\, 052403 (2006).\n\nhttps://indico.stfc.ac.u k/event/53/contributions/3712/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3712/ END:VEVENT BEGIN:VEVENT SUMMARY:Search of ultracold Mu generation material: $\\mu$SR study in SiC DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3814@indico.stfc.ac.uk DESCRIPTION:Speakers: Amba Datt Pant (IMSS\, KEK\, Japan)\nUltracold muoni um (UCMu) is an important muonium (Mu) source for the generation of ultras low muon beam [1-3] for nanotechnological applications and understanding h ydrogen dynamics in materials. In order to search a new solid material for the generation of UCMu in vacuum\, we have studied n-Si [4]\, SiC and KCl at low temperatures (5 K – 300 K) using conventional $\\mu$SR method. T he relaxation rates of Mu formed deep inside (full-stop case) and near the rear surface (half-stop case) of the samples at low transverse field (TF 1.2 G) were observed. In n-Si\, the difference in relaxation rates below 1 00K provided the hint for emission of Mu from the surface but the distance dependent study (distance of sample from silver sheet) shows that there i s surface effect that causes the change of relaxation rate of Mu in half-s top case. In SiC\, we have observed the Mu signal with high relaxation rat e and the relaxation rates in full-stop and half-stop cases were found wit hin error-bars. In KCl\, we did not observe even a complete spin rotation signal of Mu below 100 K at TF 1.2 G field. In literatures\, there is quan tum diffusion of Mu in KCl is available [5\,6]. In the program\, we will p resent details about our measurement method and result in SiC.\n\n[1] K. N agamine\, et al.\, *Phys. Rev. Lett.* **74** (24) (1995) 4811.\n[2] Y. Miy ake\, et al.\, *J. Phys. Conf. Ser.* **302** (2011) 012038.\n[3] A. D. Pan t\, et al.\, *JPS. Conf. Proc*. **21** (2018) 011060.\n[4] A. D. Pant\, et al.\, *Physica B: Physics of Condensed Matter* **613** (2021) 412997.\n[5 ] R. F. Kiefl\, et al.\, *Phys. Rev. Lett*. **62** (1989) 792.\n[6] V.G. S torchak\, et al.\, *Physica B* **374–375** (2006) 347–350.\n\nhttps:// indico.stfc.ac.uk/event/53/contributions/3814/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3814/ END:VEVENT BEGIN:VEVENT SUMMARY:The Ultra-Slow Muon beamline at J-PARC: the present status and fut ure prospects DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3815@indico.stfc.ac.uk DESCRIPTION:Speakers: Sohtaro Kanda (KEK/J-PARC)\nAt J-PARC MLF\, MUSE pro vides the world-highest flux of pulsed muon beams. U-Line\, one of the fou r beamlines in the facility\, features an intense surface muon beam from S uper-Omega and Ultra-Slow Muon (USM) generated by laser ionization of ther mal muonium in a vacuum. The beamline has two branches: U1A for muon spin spectroscopy using USMs and U1B for transmission muon microscope. The uniq ue feature of the USM is variable low-energies from sub-keV to tens of keV \, compared to the energy of 4 MeV of a surface muon beam. This feature ma kes it possible to use muons not only as a probe for the bulk but also as a depth-resolved probe for surfaces and interfaces. Commissioning of the b eamline and instruments is underway in preparation for the start of user p rograms. This contribution will present an overview of the facility\, its current status\, and its prospects.\n\nhttps://indico.stfc.ac.uk/event/53/ contributions/3815/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3815/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of a highly pixelated detector array and a novel digit ising DAE for the next generation ISIS instrument\, Super-MuSR DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3820@indico.stfc.ac.uk DESCRIPTION:Speakers: Sam Franklin (STFC)\nThe development of the next gen eration ‘Super-MuSR’ instrument at ISIS will provide a transformationa l improvement in counting rate (to 1000M ev/hr) and timing resolution (to better than 2ns) for pulsed beam measurements. Key to delivering this capa bility is the highly pixelated cylindrical detector array\, built as 64 lo ng ‘barrel staves’. This totals 704 pixels providing 75% solid angle c overage. The detector array is combined with novel readout\, where the ana logue waveforms are fully digitised and processed using digital signal pro cessing (DSP) methods at either software or firmware level. \nEach detecto r pixel will use a Hamamatsu S10362 series SiPM\, optically coupled to a BC408 scintillator using wavelength shifting fibre. The fibre is embedded into a scintillator tile\, with the ends protruding to ensure good optical coupling. The tile and fibre are surrounded by a reflective inner (PTFE) and light tight outer (Aluminium) wrapping. This design was chosen to maxi mise the light collection and homogeneity for each of the 8 different pixe l sizes used to preserve solid angle across the stave length. \nThe data p ipeline will combine a series of ‘firsts’ for ISIS. Digitisation will be achieved using the Xilinx Zynq UltraScale series of ‘system on a chip ’ operating with ADCs running at 1G Sample/s\, data handling using Kafka event streaming technology\, and full digital signal processing to provid e advanced data correction techniques.\nWe will present our design conside rations\, first results from our 12-pixel prototype stave and discuss the benefits of implementing a DSP ‘data pipeline’.\n\nhttps://indico.stfc .ac.uk/event/53/contributions/3820/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3820/ END:VEVENT BEGIN:VEVENT SUMMARY:TrimSP Simulations for Pressure Cell Stopping Fraction DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3816@indico.stfc.ac.uk DESCRIPTION:Speakers: Frank Elson (KTH\, Royal Institute of Technology)\nF or quantum systems/materials\, a standard procedure for probing this behav iour is to try to tune these properties using external parameters to put t he different phases of the material onto a phase diagram. Pressure applica tion is a widely used tool to tune these properties\, using a given pressu re cell device. This can be a problem when using Muon Spin Rotation/Relaxa tion (µ+SR) as a large proportion of the muons will be implanted in the p ressure cell rather than in the sample. This is a problem as in most cases the pressure cells give their own temperature responses. This issue gets amplified when the temperature dependant response from the sample is much smaller than that of the pressure cell\, where the sample response can be lost in the background and cause alignment issues. As pressure dependant µ+SR studies increase in popularity\, the need to tackle this issue becom es greater. We have used pySRIM **[ 1]** to make a tool that helps allevia te some of these problems\, specifically for the pressure cell setup at th e GPD beamline at the Paul Scherrer Institute\, with the use of TRIMSP sim ulations. The goal is to make it easy to estimate how many muons will be s topping in the sample and how many in the pressure cell at a given muon mo mentum. This will allow the user to know before their experiment what they expect in terms of alignment and also what kind of fractions to be inputt ing into their fit procedures to extract the background accurately. The ai m is to make this tool into an available GUI so users can easily use this before their experiment or append the simulation results to their proposal s for the GPD beamline (and maybe also other beamlines in the future).\n![ Example of simulation results][1]\n\n **[ 1]** pySRIM : https://pysrim.rea dthedocs.io/en/latest/\n\n\n [1]: https://drive.google.com/uc?id=1KXNieyI dESmVET5X7--K5NxZ9p8mo4kz\n\nhttps://indico.stfc.ac.uk/event/53/contributi ons/3816/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3816/ END:VEVENT BEGIN:VEVENT SUMMARY:Progress on Muon Source Project at CSNS DTSTART;VALUE=DATE-TIME:20220830T125000Z DTEND;VALUE=DATE-TIME:20220830T130500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3690@indico.stfc.ac.uk DESCRIPTION:Speakers: Yu Bao (Institute of High Energy Physics)\nA Muon st ation for sciEnce\, technoLOgy and inDustrY (MELODY) has been listed in th e CSNS II upgrade plan\, and the infrastructure construction is scheduled to start by the end of 2022. Up to 5Hz of proton pulses will be extracted from the RCS ring to a stand-alone target station. One surface muon and on e decay muon beamline are designed to provide multi-terminals for applicat ions. In this report\, we describe the design of MELODY and prospect for f uture applications.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/36 90/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3690/ END:VEVENT BEGIN:VEVENT SUMMARY:Status of $\\mu$SR facility in RAON DTSTART;VALUE=DATE-TIME:20220830T131500Z DTEND;VALUE=DATE-TIME:20220830T133000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3692@indico.stfc.ac.uk DESCRIPTION:Speakers: Wonjun Lee (RISP\, IBS)\nRare Isotope Science Projec t (RISP) launched in 2011 to build the Rare isotope Accelerator complex fo r ON-line experiment for rare isotope science (RAON)\, ends the 1st stage of which completes one of two main accelerators (low-energy superconductin g linac\, SCL). Since 2019\, $\\mu$SR facility has been designed and const ructed\, composed of muon production target chamber\, transport beamline\, beam dump\, except spectrometer. In this talk\, we report the current sta tus of $\\mu$SR facility in RAON as an applicative facility of RAON and a tool for investigating materials.\n\nhttps://indico.stfc.ac.uk/event/53/co ntributions/3692/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3692/ END:VEVENT BEGIN:VEVENT SUMMARY:Probing beneath the surface without a scratch: Developments of ele mental analysis using muons at ISIS DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3818@indico.stfc.ac.uk DESCRIPTION:Speakers: Adrian Hillier (STFC)\, Matteo Cataldo ()\nUsing neg ative muon emission spectroscopy (µXES) can yield unique information by d etermining the composition beneath the surface whilst being completely non -destructive and has been shown to be a powerful technique for non-destruc tive analysis of the elemental composition of precious/rare samples. The c haracteristic muonic X-rays emitted after muon implantation can be used as fingerprints to assign the presence and depth of a given element in a sam ple. The use of negative muons for elemental analysis has seen a rapid inc rease in demand\, from cultural heritage\, advanced manufacturing to energ y materials\, even though the instrument at ISIS is still under developmen t.\n\nIn the past few years there has been some developments in data acqui sition electronics\, analysis techniques\, and future instrument design an d in this paper we will review some of the science highlights\, and the re cent developments\, including:\n\nNew software has been developed (EVA) to assist in the understanding\, this includes easy peak identification\, co mposition analysis and data correction. \n\nMudirac: A Dirac equation solv er for elemental analysis with muonic X-rays is being extended to include the probability of transition\, thus potentially making an automatic effic iency and absorption correction. \n \nIn addition\, a machine learning (mu lspec_ml) based technique for analysing and classifying elemental composit ion from µXES experiments has been developed (see abstract Butler). \n\nF inally\, studies for the next generation instrument are in place. The cur rent set-up is composed by four HPGe detectors: the new detector array is expected to increase the solid angle coverage and optimisation which shoul d yield an increase in rate of 10-100x (momentum dependent) and a decrease in measuring time. To evaluate the best geometry\, Monte Carlo simulation s are performed with the GEANT4 toolkit. Simulations are peformed to evalu ate the capabilities of seven hexagonally shaped germanium crystals\, plac ed around the sample stage in a packed geometry.\n\nhttps://indico.stfc.ac .uk/event/53/contributions/3818/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3818/ END:VEVENT BEGIN:VEVENT SUMMARY:CHNET-TANDEM experiment: Muonic Atoms X-Rays Spectroscopy for elem ental characterization of ancient metal artifacts DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3819@indico.stfc.ac.uk DESCRIPTION:Speakers: Massimiliano Clemenza (INFN sezione di Milano Bicocc a)\nIn the past years\, in the framework of a successful collaboration bet ween RIKEN-RAL and INFN\, (CHNET-TANDEM collaboration) a series of experim ents were carried out to optimize Muonic Atoms X-rays Spectroscopy as a no n-invasive and non-destructive probe for quantitative elemental characteri zation of ancient metal artefacts of particular interest. We present the r esults on late Bronze-age artefacts found in Tuscany and a silver Portugue se ancient coin. A series of measurements on 2 bronze oil lamps\, with th e shape of small ships\, found in Vetulonia in the Tomb of the "Tre Navice lle"\, part of the collection of the National Archaeological Museum of Flo rence (n. inv. 6779\; 6780) and on a Portuguese coin of the eighteenth cen tury utilized for an IAEA inter comparison round robin were analysed. The goal was to determine the chemical composition of the samples with the pos sibility of carrying out both "superficial" and "bulk" measurements by ele mental profiles from the sample surface to a depth of several millimetres. \n\nhttps://indico.stfc.ac.uk/event/53/contributions/3819/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3819/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of monitoring system for the muon rotating target usin g an infrared camera DTSTART;VALUE=DATE-TIME:20220829T164000Z DTEND;VALUE=DATE-TIME:20220829T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3829@indico.stfc.ac.uk DESCRIPTION:Speakers: Shiro MATOBA (High Energy Accelerator Research Organ ization)\nIt is important to measure the temperature of the muon-productio n rotating target (hereinaf-ter referred to as "rotating target") in order to detect problems of rotating target quickly. \nThermocouples have been installed on the cooling jacket to measure the temperature rise due to the rmal radiation from the rotating tar-get. Since the time constant of the t hermocou-ples is on the order of minutes\, it is not possible to stop the accelerator quickly in case of a sig-nificant temperature rise. In order t o construct a rapid temperature detection system for rotating targets\, we have installed an infrared camera.\n We successfully measured temperature distribution of the rotating target during the 1-MW operation observed by the infrared camera.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/ 3829/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3829/ END:VEVENT BEGIN:VEVENT SUMMARY:Progress on the surface muon beamline S-Line at J-PARC MUSE DTSTART;VALUE=DATE-TIME:20220830T164000Z DTEND;VALUE=DATE-TIME:20220830T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3831@indico.stfc.ac.uk DESCRIPTION:Speakers: Akihiro Koda (KEK IMSS)\nThe surface muon beamline ( S-Line) in the experimental hall No.1 of the Materials and Life science ex perimental Facility (MLF)\, J-PARC is designed to provide low-energy muon beam\, which is mainly utilized by materials and life science experiments. The final goal of S-Line is a beamline with four experimental areas from S1 to S4\, of which the first experimental area S1 started in 2017 for use r experiment programs. In 2022\, beam tests in the second experimental are a S2 finally started\, where a group led by Prof. Uetake at Okayama Univer sity has set up an apparatus for laser spectroscopy of muonium. Using the electric beam kicker in the S line\, a double-pulse muon beam can be used as a single-pulse muon beam in the S1 and S2 areas simultaneously. Beam co mmissioning started in January 2022 confirmed that 3x10^6 /s of positive m uons are extracted to the S2 area when the proton beam of 700 kW is operat ed. Besides\, we have had several beam kicker problems due to failures in the Marx high voltage circuits using semiconductor devices. It is the beam line component that requires improvement for stable operation at the highe st priority.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3831/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3831/ END:VEVENT BEGIN:VEVENT SUMMARY:Thermal integrity test to muon production target by the induction heating system DTSTART;VALUE=DATE-TIME:20220901T164000Z DTEND;VALUE=DATE-TIME:20220901T170000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3830@indico.stfc.ac.uk DESCRIPTION:Speakers: Wonjun Lee (RISP\, IBS)\nWe report progress of which examines the thermal stability of the muon production target up to high t emperature regime. We employed the high-frequency induction heating system as an indirect heater to target material\, graphite\, used with various p urposes such as kitchenware\, small blacksmiths. Prior to applying muon pr oduction target\, we tested simple disc graphite with small chamber and RF feedthrough made by stainless steel\, heat was delivered well to graphite \, but metal RF feedthrough is bad for high temperature due to heating-up. We designed the flange for RF coil and supporters made by acetal (polyoxy methylene\, POM). Tested with small chamber again\, it worked under high v acuum condition (10$^{-7}$ torr) and high temperature with full power load ed\, but still plastic components are damaged by high temperature due to c lose to heating source. The thermal test is undertaken systematically at m uon production chamber\, combined with the engineering simulations\, Ansys Mechanical/Maxwell simultaneously. This may be significant method to test various target as a thermal aspect without beam irradiation.\n\nhttps://i ndico.stfc.ac.uk/event/53/contributions/3830/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3830/ END:VEVENT BEGIN:VEVENT SUMMARY:Development and test of a TDC and amplifier circuit for a multi-ch annel positron detector. DTSTART;VALUE=DATE-TIME:20220828T114500Z DTEND;VALUE=DATE-TIME:20220828T120000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3672@indico.stfc.ac.uk DESCRIPTION:Speakers: Marta-Villa de Toro Sanchez (Centre for Molecular an d Materials Science\, TRIUMF – School of Physics and Astronomy\, The Uni versity of Edinburgh)\nIn a continuous beam muon facility positrons are de tected by relatively large plastic scintillators without position sensitiv ity. An idea has been proposed to make these positron detectors multi-chan nel and able to track the positron trajectories. This will ultimately enab le 2-dimensional magnetic imaging of the sample with the µSR technique. T o attain this “muon microscope” idea\, large numbers of independent ph otosensors with high-timing resolution will be necessary.\n\nOur group at KEK has developed an amplifier-shaper-discriminator (ASD) circuit named FG ATI with 16 channels per chip and a high-resolution time to digital conver ter\, called HR-TDC with a timing resolution on the order of picoseconds. Silicon photomultipliers (SiPMs) from Hamamatsu (MPPC) are employed to giv e electric pulses for the optical input [1-2]. We have been testing this n ew set-up at TRIUMF with a pulsed laser to understand the efficiency\, tra nsient response\, timing resolution\, and the data acquisition to a comput er. We are now successfully detecting the rising and falling edge timing a s well as the time-over-threshold (TOT) of the laser pulses.\n\nThe tested circuit will be a basis for the light detection and time recording from s cintillation fiber arrays to be used for the multi-channel positron detect ors. Multiple layers of such detectors will establish tracking the positro n trajectory and aid with the development of the “muon microscope”.\n\ nThis work is partially supported by a Grant-in-Aid for Scientific Researc h (No.JP21H04666) from Japan Society for the Promotion of Science (JSPS).\ n\nReference\n[1] K.M. Kojima et al\, JPS Conf. Proc.\, 21\, 011062 1-6\, (2018).\n[2] K.M. Kojima et al\, J. Phys: Conf. Ser.\, 551\, 012063\, (201 4).\n![enter image description here][1]\n![enter image description here][2 ]\n\n\n [1]: http://file:///Users/martadetoro/Desktop/Captura%20de%20Pant alla%202022-06-09%20a%20la(s)%209.30.54%20a.%20m..png\n [2]: http://file: ///Users/martadetoro/Desktop/Captura%20de%20Pantalla%202022-06-09%20a%20la (s)%209.31.05%20a.%20m..png\n\nhttps://indico.stfc.ac.uk/event/53/contribu tions/3672/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3672/ END:VEVENT BEGIN:VEVENT SUMMARY:Final Discussion DTSTART;VALUE=DATE-TIME:20220830T142000Z DTEND;VALUE=DATE-TIME:20220830T143000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3850@indico.stfc.ac.uk DESCRIPTION:https://indico.stfc.ac.uk/event/53/contributions/3850/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3850/ END:VEVENT BEGIN:VEVENT SUMMARY:Quantum critical spin-liquid behavior in $S = 1/2$ quasikagome lat tice CeRh$_{1-x}$Pd$_{x}$Sn investigated using muon spin relaxation DTSTART;VALUE=DATE-TIME:20220831T102000Z DTEND;VALUE=DATE-TIME:20220831T104000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3642@indico.stfc.ac.uk DESCRIPTION:Speakers: Rajesh Tripathi (Rutherford Appleton Laboratory ISIS Facility\, UK & Jawaharlal Nehru Center for Advanced Scientific Research Bangalore India )\nWe present the results of muon spin relaxation ($\\mu$S R) on the Ce-based quasikagome lattice CeRh$_{1-x}$Pd$_{x}$Sn ($x$ = 0.1 t o 0.5). Our zero-field (ZF) $\\mu$SR results reveal the absence of both st atic long-range magnetic order and spin freezing down to 0.05 K in the sin gle crystal sample of $x = 0.1$. The weak temperature-dependent plateaus o f the dynamic spin fluctuations below 0.2 K in ZF-$\\mu$SR together with i ts longitudinal-field (LF) dependence between 0 and 3 kG indicate the pres ence of dynamic spin fluctuations persisting even at $T$ = 0.05 K without static magnetic order. On the other hand\, the magnetic specific heat divi ded by temperature $C_{\\text{4f}}$/$T$ increases as -log $T$ on cooling b elow 0.9 K\, passes through a broad maximum at 0.13 K and slightly decreas es on further cooling. The ac-susceptibility ($\\chi_{\\text{ac}}$) also e xhibits a frequency independent broad peak at 0.16 K\, which is prominent with an applied field $H$ along the $c$-direction. We\, therefore\, argue that such behavior for $x=0.1$ (namely\, a plateau in the spin relaxation rate ($\\lambda$) below 0.2 K and a linear $T$-dependence in $C_{\\text{4f }}$ below 0.13 K) can be attributed to a metallic spin-liquid (SL) ground state near the quantum critical point (QCP) in the frustrated Kondo lattic e. The LF-$\\mu$SR study suggests that the out of kagome plane spin fluctu ations are responsible for the SL behavior. The ZF-$\\mu$SR results for th e $x = 0.2$ polycrystalline sample exhibits similar behavior to that of $x = 0.1$. A saturation of $\\lambda$ below 0.2 K suggests a spin-fluctuatin g SL ground state down to 0.05 K. The ZF-$\\mu$SR results for the $x = 0.5 $ sample are interpreted as a long-range antiferromagnetic (AFM) ground st ate below $T_{\\text{N}}$ = 0.8 K\, in which the AFM interaction of the en larged moments probably overcomes the frustration effect.\n\nhttps://indic o.stfc.ac.uk/event/53/contributions/3642/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3642/ END:VEVENT BEGIN:VEVENT SUMMARY:MuSpinSim: spin dynamics calculations for muon science. DTSTART;VALUE=DATE-TIME:20220831T084000Z DTEND;VALUE=DATE-TIME:20220831T090000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3657@indico.stfc.ac.uk DESCRIPTION:Speakers: Leandro Liborio (Scientific Computing Department\, R utherford Appleton)\nMuSpinSim is a Python software to simulate muon ($\\m u$SR) experiments. In particular\, it simulates the spin dynamics of a sys tem of a muon plus other spins such as electrons and atomic nuclei. MuSpin Sim can simulate various common experimental setups used in $\\mu$SR\, suc h as zero\, transverse and longitudinal field experiments\; and it can sim ulate $\\mu$SR experiments that are resolved in time\, field\, or temperat ure. Furthermore\, MuSpinSim can account for the effects of hyperfine\, di polar\, quadrupolar and Zeeman couplings\, as well as simulate quantum sys tems exchanging energy with the environment with the Lindblad master equat ion. Finally\, MuSpinSim can be used to fit experimental $\\mu$SR data wit h simulations that use all of the capabilities described above. The fittin gs can be run in parallel on multiple cores\, which significantly reduces the computational cost of the most expensive tasks. In this work\, we pre sent the Python package MuSpinSim with all the utilities it provides to fa cilitate simulations of $\\mu$SR experiments\, demonstrate the effectivene ss of the method with some chosen example systems and show a prototype app lication of MuonGalaxy\, a web-based implementation of MuSpinSim that is b ased on the [Galaxy platform][1].\n\n\n [1]: http://galaxyproject.org/\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3657/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3657/ END:VEVENT BEGIN:VEVENT SUMMARY:Nuclear magnetic resonance of $^8$Li ions implanted in ZnO DTSTART;VALUE=DATE-TIME:20220828T093000Z DTEND;VALUE=DATE-TIME:20220828T094500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3668@indico.stfc.ac.uk DESCRIPTION:Speakers: Jonah Adelman (University of British Columbia)\nZnO is a wide direct bandgap (3.4 eV) semiconductor with promising electronic properties potentially useful in room temperature optoelectronic and spint ronic devices. It can be used as a dilute magnetic semiconductor by tuning intrinsic or extrinsic magnetic defects while ZnO also demonstrates many unique surface effects such as a photogenerated metallic state. Imperative to utilizing these unique properties is understanding and controlling poi nt defects in its hexagonal wurtzite structure that may lead to stable hol e doping. We implanted a low energy (20-25 keV) beam of hyperpolarized spi n-2 8Li ions and used β-detected nuclear magnetic resonance (β-NMR) to u nderstand the stability\, structure\, and magnetic state of Li defects in ZnO [Adelman et al.\, arXiv:2109.08637v1]. Closely related to μSR used to characterize isolated hydrogen impurities in ZnO\, β-NMR allows compleme ntary investigations of light isotope dopants in the ultradilute limit.\n\ nUsing 8Li simultaneously as the defect and probe\, distinct Li sites are detected by measuring the coupling of the nuclear electric quadrupole mome nt to the asymmetric electronic charge distribution surrounding the 8Li nu cleus. From 7.6 to 400 K\, we find ionized shallow donor interstitial Li i s exceptionally stable\, verifying its role in self-compensation of the ac ceptor (Zn) substitutional. Like the interstitial\, the substitutional def ect shows no resolved hyperfine field above 210 K\, indicating it is a sha llow acceptor. By pulsing the 8Li beam\, the spin-lattice relaxation is me asured and indicates above 300 K the onset of correlated local motion of i nteracting defects. This is supported by resonance spectra collected with a CW frequency comb that enhances the amplitude of well-resolved quadrupol ar multiplets and confirms a site change transition from disordered inters titial Li to the substitutional. The quadrupole hyperfine interaction exhi biting a T3/2 temperature dependence typical of non-cubic metals is also d iscussed.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3668/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3668/ END:VEVENT BEGIN:VEVENT SUMMARY:Possible p-wave parity in Cr-based superconductor Pr$_3$Cr$_{10-x} $N$_{11}$ DTSTART;VALUE=DATE-TIME:20220828T121500Z DTEND;VALUE=DATE-TIME:20220828T123000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3674@indico.stfc.ac.uk DESCRIPTION:Speakers: Changsheng Chen (Fudan University)\nSuperconductivit y with a critical temperature $T_C$ $\\sim$ 5.25 K was recently reported i n the Cr-based superconductor Pr$_3$Cr$_{10-x}$N$_{11}$. The large upper c ritical field $H_{C2}$ $\\sim$ 20 T\, and the strong correlation between 3 $d$ electrons derived from specific heat\, suggest the unconventional supe rconductivity nature of this compound. We performed muon-spin rotation/rel axation ($\\mu$SR) measurements on a high-quality polycrystalline of Pr$_3 $Cr$_{10-x}$N$_{11}$ down to 0.027 K\, and specific heat measurements unde r different magnetic fields up to 9 Tesla. Our $\\mu$SR data indicate that time-reversal symmetry is broken in the superconducting state of Pr$_3$Cr $_{10-x}$N$_{11}$\, and the superconducting energy gap is consistent with a $p$-wave model\, which is also supported by the specific heat data.\n\nh ttps://indico.stfc.ac.uk/event/53/contributions/3674/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3674/ END:VEVENT BEGIN:VEVENT SUMMARY:A wolf in sheep's clothing? Muon-induced magnetism in quantum spin ice DTSTART;VALUE=DATE-TIME:20220828T094500Z DTEND;VALUE=DATE-TIME:20220828T100000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3669@indico.stfc.ac.uk DESCRIPTION:Speakers: Hank Wu (Oxford University)\nCompounds of the form $ \\rm{A}_2\\rm{X}_2\\rm{O}_7$ with the pyrochlore structures can exhibit cl assical or quantum spin ice behaviour if the crystal field environment of the $\\rm{A}\\rm{O}_8$ arrangement leads to the [111] easy-axis anisotropy . When Pr occupies the A-site\, there is a low-lying electronic doublet an d $\\rm{Pr}_2\\rm{X}_2\\rm{O}_7$ compounds are found to be quantum spin ic es$^1$. Pr$^{3+}$ is a non-Kramers ion and the presence of the muon can di stort nearby $\\rm{PrO}_8$ units and split the doublet ground states$^2$\, resulting in an enhancement of the Pr nuclear moment due to hyperfine cou pling with the electronic moments$^3$. We explore this effect using a theo retical model that takes account of the important interactions and compare our simulations with $\\mu$SR data on samples of $\\rm{Pr}_2\\rm{X}_2\\rm {O}_7$ (X = Sn\, Hf\, Zr) and new experimental data on $\\rm{Pr}_2\\rm{ScT aO}_7$\, a candidate system that simultaneously realises spin ice and char ge ice structures.\n\n\nReferences:\n1. A. Princep\, *Phys. Rev. B* **88** \, 104421 (2013)\n2. F. Foronda et al.\, *Phys. Rev. Lett.* **114**\, 0176 02 (2015)\n3. B. Bleaney\, *Physica* **69**\, 317 (1973)\n\nhttps://indico .stfc.ac.uk/event/53/contributions/3669/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3669/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of magnetic resonance imaging (MRI) system using beta- NMR technique DTSTART;VALUE=DATE-TIME:20220828T133000Z DTEND;VALUE=DATE-TIME:20220828T134500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3677@indico.stfc.ac.uk DESCRIPTION:Speakers: Takato Sugisaki (Dept. Phys. Osaka Univ.)\nToday\, t he technology of magnetic resonance imaging (MRI) has been established and it is essential in the medical field. MRI is the method of making an in-s itu image by utilizing nuclear magnetic resonance (NMR). However\, the MRI technique has rarely been put to practical use for elements other than hy drogen because of the sensitivity issue. On the other hand\, the technique of beta-ray-detecting NMR (beta-NMR) makes it possible to observe NMR for various elements with extremely high sensitivity by measuring the asymmet ry of the beta-ray emission from polarized radioisotopes (RIs). By utilizi ng beta-NMR\, we aim to create a 3-dimensional (3D) MRI system. We have de veloped a detector set with plastic scintillation fibers\, which enables u s to track back the trajectory of beta-rays. Moreover\, by seeking the bet a-ray asymmetry at each position in the sample\, we can create a magnetic resonance image. We conducted experiments using a spin-polarized $^{12}\\ rm{B}$($I=1\,T_{1/2}=20\\\;\\rm{ms}$) beam at HIMAC heavy-ion synchrotron facility of the National Institutes for Quantum Science and Technology. We obtained the data from various samples of mixtures as well as simple subs tances. We have successfully obtained a 1D image of the beta-ray asymmetry for $^{12}\\rm{B}$ in Si. The data analysis for 3D imaging are now in pro gress.\nIt is expected that this new technique will be applied to non-dest ructive and non-contact testing related to various fields such as medical and materials science.\nIn this conference\, we will present our new resul ts of the analyses. We will also show some idea that a combination of beta -NMR and mu-SR will expand this technique.\n\nhttps://indico.stfc.ac.uk/ev ent/53/contributions/3677/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3677/ END:VEVENT BEGIN:VEVENT SUMMARY:Yamazaki Prize Giving DTSTART;VALUE=DATE-TIME:20220829T072000Z DTEND;VALUE=DATE-TIME:20220829T074000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3853@indico.stfc.ac.uk DESCRIPTION:https://indico.stfc.ac.uk/event/53/contributions/3853/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3853/ END:VEVENT BEGIN:VEVENT SUMMARY:Studying the evolution of the metallic state in LaNiO$_3$ from a s ingle crystal to superlattices with $\\beta$-detected NMR DTSTART;VALUE=DATE-TIME:20220829T104000Z DTEND;VALUE=DATE-TIME:20220829T110000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3647@indico.stfc.ac.uk DESCRIPTION:Speakers: W. Andrew MacFarlane (UBC)\nThe rare-earth nickelate s (RNiO$_3$) are a prototypical example of a metal-insulator transition. A mong the RNiO$_3$\, LaNiO$_3$ is unique in remaining metallic\, although h ighly correlated. Interestingly\, superlattices with insulating interlayer s of LaAlO$_3$\, can be driven insulating and antiferromagnetic if they ar e thin enough$^{1}$. We have used $^8$Li $\\beta$-detected NMR ($\\beta$-N MR)\, to study LaNiO$_3$ as a single crystal\, thin film\, and in superlat tices with LaAlO$_3$. We observe biexponential spin-lattice relaxation wh ich we attribute to electronic phase separation$^{2\,3}$. In the single cr ystal and bulk-like thin film\, both phases appear metallic$^{2}$. However \, in the ultrathin layers of the superlattices\, the behaviour of one of the phases appears magnetic at low temperature$^{3}$. \n1. A. V. Boris et al.\, Science 332\, 937 (2011)\n2. V. L. Karner et al.\, Phys. Rev. B 100\ , 165109 (2019)\n3. V. L. Karner et al.\, Phys. Rev. B. 104\, 205114 (2021 )\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3647/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3647/ END:VEVENT BEGIN:VEVENT SUMMARY:Non-destructive operando measurements of muonic x-rays on Li-ion b attery DTSTART;VALUE=DATE-TIME:20220829T142000Z DTEND;VALUE=DATE-TIME:20220829T144000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3662@indico.stfc.ac.uk DESCRIPTION:Speakers: Izumi Umegaki (KEK\, Toyota Central R&D Labs.\, Inc. )\nWe have developed an elemental analysis technique with muonic x-ray on a Li-ion battery\, taking advantages of muon and muonic x-rays\, that is\, accessibility of negative muons and high energy of muonic x-rays[1\,2]. E specially\, intense negative muon with low momentum at J-PARC enables us t o investigate electrodes in Li-ion battery. There is no non-destructive me thod to observe Li directly deep inside the Li-ion battery. Elemental anal ysis with muonic x-rays has great advantages for that.\n\nWe have recently performed operando measurements of muonic x-rays on aLi-ion battery at J- PARC for the first time. By this technique\, we have demonstrated the inte rcalation of Li in a cathode during charging and discharging. Also\, we fo und that we can detect metallic Li deposition on a negative electrode usin g a difference in capture rates between metallic Li and C$_6$Li[3]. Using this technique\, observing an increase in the metallic Li deposition durin g high-rate charge/discharge cycles is expected to be realized. \n\nWe wil l show the progress in operando measurements of muonic x-rays to study Li- ion batteries at J-PARC.\n\n\n[1] M. Tampo et al.\, Proceedings of MuSR201 4\, JPS Conf. Proc.8\, 036016\,(2015).\n[2] I. Umegaki et al.\,"Detection of Li in Li-ion battery electrodes by muonic x-ray elemental analysis"\, M uSR2017.\n[3] I. Umegaki et al.\, Analytical Chemistry\, 92\, 12\,8194-820 0 (2020).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3662/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3662/ END:VEVENT BEGIN:VEVENT SUMMARY:Exploting magnetic interactions in Kitaev anti-ferromagnet Na$_{2} $PrO$_{3}$ DTSTART;VALUE=DATE-TIME:20220829T092000Z DTEND;VALUE=DATE-TIME:20220829T094000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3643@indico.stfc.ac.uk DESCRIPTION:Speakers: Jonathan Frassineti (University of Bologna)\nOur goa l is to analyze the magnetic properties of the Kitaev material Na$_{2}$PrO $_{3}$ by comparing Neutron Scattering (NS) and Muon Spin Spectroscopy ( μSR) experiments\, with the addition of ab initio calculations. \n\nAlkal i-metal lanthanide oxides are an exciting field of study due to their frus trated geometry and possibly anisotropic magnetic interactions\, as shown in Fig.1. \n\n![Schematic diagram of Kitaev honeycomb lattice\, with aniso tropic bond interactions $J_{x}$\, $J_{y}$\, $J_{z}$.][1]\n\nIn this class of materials\, also known as Kitaev materials\, the SOC energy is compara ble to that induced by crystal-field excitations (CEF)\, and the small spa tial extent of f-electron orbitals promotes anisotropic Kitaev terms. \n\n Na$_{2}$PrO$_{3}$ crystallizes with a monoclinic unit cell\, where edge-sh aring PrO$_{6}$ octahedra forms a honeycomb lattice. The effective paramag netic moment is 0.99 μB\, less than the free Pr$^{4+}$ ion moment (2.54 μB)\, and the origin of its small value is still under debate. In additio n\, it displays a magnetic ordering transition at $T_{N}$ = 4.6 K. Previou s powder diffraction measurements could not detect any signs of magnetic o rdering\, despite evidence in specific heat and magnetometry measurements. Moreover\, preliminary magnetic neutron diffraction results do not reveal any clear magnetic Bragg peaks\, probably due to the low value of Na$_{2} $PrO$_{3}$ effective paramagnetic moment. \n\nThe principal question that motivated our work was to try to explain the small effective paramagnetic moment\, considering the presence of the magnetic ordering. Thanks to the muon’s extreme sensitivity to small-moment magnetism\, here μSR is high ly relevant. From this\, Na$_{2}$PrO$_{3}$ shows coherent oscillations of the muon asymmetry below $T_{N}$\, reflecting the presence of an anti-ferr omagnetic (AFM) ordering. \n\nIn comparison with experimental data\, combi ned ab initio calculations and dipolar simulations were performed in order to elucidate the nature of AFM ordering inside this material and to try t o explain the small value of the effective paramagnetic moment. \n\n\n [1 ]: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTHAUSw9gHpNLBm7bd bxSubER6i_KD0qkDEZA&usqp=CAU\n\nhttps://indico.stfc.ac.uk/event/53/contrib utions/3643/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3643/ END:VEVENT BEGIN:VEVENT SUMMARY:Time-reversal symmetry-breaking charge order in a kagome supercond uctor DTSTART;VALUE=DATE-TIME:20220829T124000Z DTEND;VALUE=DATE-TIME:20220829T130000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3653@indico.stfc.ac.uk DESCRIPTION:Speakers: Zurab Guguchia (Laboratory for Muon Spin Spectroscop y\, Paul Scherrer Institute\, Switzerland)\nThe kagome lattice\, the most prominent structural motif in quantum physics\, benefits from inherent non trivial geometry to host diverse quantum phases\, ranging from spin-liquid phases\, topological matter to intertwined orders\, and most rarely uncon ventional superconductivity. Recently\, charge sensitive probes have sugge sted that the kagome superconductors AV3Sb5 (A = K\, Rb\, Cs) [1] exhibit unconventional chiral charge order. However\, direct evidence for the time -reversal symmetry-breaking of the charge order remained elusive. We utili zed muon spin relaxation to probe the kagome charge order and superconduct ivity in (K\,Rb)V3Sb5 [2\,3]. We observe a striking enhancement of the int ernal field width sensed by the muon ensemble\, which takes place just bel ow the charge ordering temperature and persists into the superconducting s tate. Remarkably\, the muon spin relaxation rate below the charge ordering temperature is substantially enhanced by applying an external magnetic fi eld. We further show [3] that the superconducting state displays a reduced superfluid density\, which can be attributed to the competition with the novel charge order. Upon applying pressure\, the charge-order transitions are suppressed\, the superfluid density increases\, and the superconductin g state progressively evolves from nodal to nodeless. Our results point to the rich interplay and accessible tunability between unconventional super conductivity and time-reversal symmetry-breaking charge orders in the corr elated kagome lattice\, offering new insights into the microscopic mechani sms involved in both orders.\n\n[1] Y.-X. Jiang et. al.\, Nature Materials 20\, 1353 (2021). \n[2] C. Mielke et. al.\, and Z. Guguchia\, Nature 602\ , 245-250 (2022).\n[3] Z. Guguchia et. al.\, arXiv:2202.07713v1 (2022).\n\ nhttps://indico.stfc.ac.uk/event/53/contributions/3653/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3653/ END:VEVENT BEGIN:VEVENT SUMMARY:Profiling defect and charge carrier density in the SiO$_2$/4H-SiC interface with Low-Energy Muons DTSTART;VALUE=DATE-TIME:20220828T131500Z DTEND;VALUE=DATE-TIME:20220828T133000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3676@indico.stfc.ac.uk DESCRIPTION:Speakers: Maria Mendes Martins (Laboratory for Muon Spin Spect roscopy\, Paul Scherrer Institute)\nSilicon carbide (4H-SiC) is a wide-ban dgap semiconductor with promising applications in high-power and high-freq uency devices. An advantage of SiC is that it is the only compound semicon ductor that has the ability to form native silicon dioxide (SiO$_2$). The performance of SiC-based devices relies heavily on interface effects. Howe ver\, characterization of oxidation-induced defects - both in the oxide a nd the semiconductor - is still challenging.\nLow-energy muon spin spectro scopy (LE-$\\mu$SR) can probe regions very close to the surface and interf ace up to a depth of 160 nm in SiO$_2$/SiC structures and is sensitive to charge carrier and defect concentrations.\n\nWe have studied SiO$_2$/SiC i nterfacial systems with thermally grown and deposited oxides using LE-$\\m u$SR. The thermal SiO$_2$ has higher structural order\, as indicated by th e undisturbed muonium (Mu$^0$) formation. However\, the oxidation process leads to strain in the oxide and to band-bending at the SiC-side of the in terface\, which affects the SiC faces differently: i) at the (0001) Si-fac e the results can be explained by the depletion of electrons at the interf ace and ii) at the (000$\\overline{1}$) C-face a carbon-rich n-type region contributes to the increase of the diamagnetic fraction due to Mu$^-$ for mation.\nFurther investigations have been conducted to understand the pass ivation effects of state-of-the-art post-oxidation annealing (POA) process es on the SiO$_2$/SiC interface. Particularly\, POA in an NO environment l eads to an increase in charge carrier concentration near the interface\, l ikely due to N acting as a dopant\, which can be quantified based on the m easured diamagnetic fraction.\n\nhttps://indico.stfc.ac.uk/event/53/contri butions/3676/ LOCATION: Aula dei Cavalieri\, University Central Palace\, via Università 12 URL:https://indico.stfc.ac.uk/event/53/contributions/3676/ END:VEVENT BEGIN:VEVENT SUMMARY:H2 storage mechanism in fullerides studied with μSR DTSTART;VALUE=DATE-TIME:20220830T093000Z DTEND;VALUE=DATE-TIME:20220830T095000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3624@indico.stfc.ac.uk DESCRIPTION:Speakers: Daniele Pontiroli (Nanocarbon Laboratory\, Dipartime nto di Scienze Matematiche\, Fisiche e Informatiche & INSTM\, Università degli Studi di Parma\, 43124 Parma\, Italy)\nWhen positive muons (µ+) are implanted in insulating materials\, they capture electrons to form muoniu m (Mu)\, a light isotope of H. This process makes muon spin resonance tech nique (µ SR) suitable for studying H interaction with matter\, for exampl e in hydrogen storage (HS) materials.\nAmong carbon-based materials\, rece ntly metal intercalated fullerides demonstrated to be promising for HS\, r epresenting de-facto a novel class of HS compounds: in particular\, it has been shown that both lithium and sodium cluster intercalated fullerides c an reversibly absorb relevant amount of hydrogen (up to 5 wt % in case of Li6C60)\, at thermodynamic conditions much milder than what observed in pu re C60. However\, the hydrogenation mechanism in these systems is not triv ial and involves several processes\, difficult to disentangle with convent ional techniques.\nIn this work we show how uSR helped us to shed light on the hydrogenation process of these systems. In detail\, we performed a µ SR investigation of Li6C60 and Na10C60\, either as-prepared or after hydro genation\, on the EMU and ARGUS beamlines\, at ISIS-RAL. Interestingly\, w e found that in these compounds the formation of muonium is not inhibited\ , thanks to the presence of the intercalated partly ionized alkali cluster s. Muonium was found to react with C60 to form adduct radicals\, appearing as a missing fraction in the muon spin signal. This phenomenon is depende nt on temperature and is invariably enhanced on cooling for all the invest igated samples. \nSuch findings indicated that in these systems C60 hydrog enation is already feasible at cryogenic temperatures\, with an efficiency even larger than at high T\, while the high T needed for hydrogen storage in fullerides is only required to overcome the alkali metals mediated H2 dissociation barrier. Following this hint\, we managed to further enhance the hydrogen absorption by co-intercalating transition metals nanoparticle s (Pt\, Pd) in the fullerides interstices.\n\nhttps://indico.stfc.ac.uk/ev ent/53/contributions/3624/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3624/ END:VEVENT BEGIN:VEVENT SUMMARY:Negative muon spin rotation and relaxation for energy materials DTSTART;VALUE=DATE-TIME:20220830T101000Z DTEND;VALUE=DATE-TIME:20220830T103000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3626@indico.stfc.ac.uk DESCRIPTION:Speakers: Jun Sugiyama (CROSS Neutron Science and Technology C enter)\nA positive muon spin rotation and relaxation ($\\mu^{+}$SR) has be en widely used for assorted materials to study a microscopic internal magn etic field. However\, the counterpart technique\, $\\mu^{-}$SR\, is less c ommon mainly due to a small asymmetry of the $\\mu^{-}$SR signal\, typical ly 1/6 to that of $\\mu^+$SR\, caused by the loss of the spin polarization during a capture process of $\\mu^-$ by nuclei. This means that 36 times higher statistics are needed for $\\mu^{-}$SR measurements to achieve a re liability comparable with the one of $\\mu^{+}$SR. Fortunately\, recent de velopments of the intense pulsed muon beam together with a multi-detectors counting system enable the measurement of the $\\mu^{-}$SR spectrum withi n a reasonable amount of beamtime. As a result\, we have developed a new t ool to detect internal magnetic fields from a fixed view point\, since the muonic atom (the bound state between $\\mu^-$ and an element of the targe t material) should be stable up to the decomposition temperature of target materials. This is particularly important for research on energy material s\, in which various atoms and/or ions are diffusing and such species coul d affect the local stability of the implanted $\\mu^+$ at the interstitial site. Here\, we summarize our $\\mu^{-}$SR results on hydrogen storage ma terial MgH$_2$ [1]\, cathode materials of ion batteries LiMnPO$_4$ [2] and Li[Ni$_{1/2}$Mn$_{3/2}$]O$_4$ [3]\, and an anode material Li$_4$Ti$_5$O$_ {12}$ [4].\n\n[1] J. Sugiyama et al.\, Phys. Rev. Lett. ${\\bf 121}$\, 087 202 (2018).\n[2] J. Sugiyama et al.\, Phys. Rev. Research ${\\bf 2}$\, 033 161 (2020).\n[3] J. Sugiyama et al.\, Z. Phys. Chem. ${\\bf 236}$\, 799 (2 022).\n[4] I. Umegaki et al.\, J. Phys. Chem. C ${\\bf 126}$\, 10506 (2022 ).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3626/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3626/ END:VEVENT BEGIN:VEVENT SUMMARY:Present status of J-PARC MUSE DTSTART;VALUE=DATE-TIME:20220830T122000Z DTEND;VALUE=DATE-TIME:20220830T123500Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3688@indico.stfc.ac.uk DESCRIPTION:Speakers: Koichiro Shimomura (KEK/J-PARC)\nJ-PARC MUSE is resp onsible for the inter-university user program and the operation\, maintena nce\, and construction of the muon beamlines\, namely D-line\, S-line\, U- line\, and H-line\, along with the muon source at MLF. \nAt D-line\, which provides the world’s most intense pulsed negative and positive muon bea ms\, various scientific studies\, including those on industrial applicatio ns\, archeology\, and fundamental physics\, have been performed. In FY2021 \, non-destructive analysis was carried out on samples brought back by Hay abusa2 from the asteroid Ryugu\, which are thought to preserve the element al composition of the solar system in its primordial state. \nStable opera tions have been achieved in S1 area of S-line for μSR. In addition\, a gr oup at Okayama University constructed a new experimental area\, S2\, in FY 2020 for muonium 1s-2s measurement. \nU-line\, uses electrostatic lenses t o focus low-energy muons obtained by laser ionization of thermal muonium t o produce energy-variable and high time-resolution ultra-slow pulsed muon beams for various experiments. A muon spin spectrometer for materials scie nce research using the μSR method has been installed in the U1A area\, an d is being upgraded and upgraded for the start of the inter-university use r program. The spectrometer is located on a high-voltage stage and the dep th of penetration into the sample can be controlled in the range from sub- keV to 30 keV.\nThe H line is a high-intensity muon beamline where experim ents such as high-statistics fundamental physics experiments and transmiss ion muon microscopy are planned. The first beam observed in the H1 experim ental area\, the first branch\, in January 2022.\nAt present\, the beam co mmissioning is being carried out in collaboration with several research gr oups that plan to conduct experiments at the H-line.\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3688/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3688/ END:VEVENT BEGIN:VEVENT SUMMARY:Muons and cultural heritage - Quantum Magic DTSTART;VALUE=DATE-TIME:20220901T160000Z DTEND;VALUE=DATE-TIME:20220901T173000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3854@indico.stfc.ac.uk DESCRIPTION:Speakers: Massimiliano Clemenza (INFN Sezione Milano Bicocca)\ , Raffaele Silvani ()\nThe event language is Italian\n\nhttps://indico.stf c.ac.uk/event/53/contributions/3854/ LOCATION:APE Parma Museo - Strada Farini 32/a URL:https://indico.stfc.ac.uk/event/53/contributions/3854/ END:VEVENT BEGIN:VEVENT SUMMARY:Quantum spin liquid behavior in geometrically frustrated Mo pyroch lore antiferromagnet Lu$_2$Mo$_2$O$_{5-y}$N$_2$ DTSTART;VALUE=DATE-TIME:20220831T104000Z DTEND;VALUE=DATE-TIME:20220831T110000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3739@indico.stfc.ac.uk DESCRIPTION:Speakers: Sourav K. Dey (IMSS\, KEK)\, Ryosuke Kadono (IMSS\, KEK)\nThe magnetic ground state of a quantum spin liquid (QSL) candidate c ompound\, Lu$_2$Mo$_2$O$_{5-y}$N$_2$ oxynitride pyrochlore ($S=1/2$\, Mo$^ {5+}$)\, was investigated by muon spin rotation/relaxation experiment. In contrast to Lu$_2$Mo$_2$O$_7$ ($S=1$\, Mo$^{4+}$) which exhibits a spin g lass-like freezing of Mo moments below $T_g\\simeq16$ K\, no such spin fre ezing or long range magnetic order was observed down to 0.3 K. More intere stingly\, two distinct magnetic domains discerned by spin dynamics were ob served below $\\sim$13 K\; one showing the ``sporadic'' spin fluctuation s imilar to that observed in other QSL candidate compounds including the kag ome antiferromagnets\, and the other showing the fast paramagnetic fluctua tion that is only weakly suppressed with decreasing temperature. Their o rigins are discussed in terms of the bond randomness induced by the partia l substitution of O with N and the inhomogeneous Mo valency due to O defic iency ($y>0$) [1].\n\nReferences\n[1] S. K. Day *et al.*\, arXiv:2206.1304 9.\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3739/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3739/ END:VEVENT BEGIN:VEVENT SUMMARY:Unconventional pressure dependence of the superfluid density in to pological superconductor α−PdBi2 DTSTART;VALUE=DATE-TIME:20220901T094000Z DTEND;VALUE=DATE-TIME:20220901T100000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3650@indico.stfc.ac.uk DESCRIPTION:Speakers: Debarchan Das (Paul Scherrer Institute)\nThe Pd-Bi f amily of compounds has become quite popular system to explore topological superconductivity due to their intrinsic capability to maintain strong spi n orbit coupling (SOC). Amongst various members of this family\, $\\alpha$ -PdBi$_2$ turns out to be very promising due to its superconducting ($T_c$ = 1.7 K) as well as topological properties such as Dirac point at 1.26 eV below the Fermi energy at the zone center\, Rashba state near the Fermi e nergy etc. Notably\, the ARPES data display multiple band crossings at the Fermi energy which signals a possible multiple gap superconducting gap st ructure in this compound. To explore this interesting aspect\, we investig ated the superconducting properties of the topological superconductor α-P dBi2 at ambient and external pressures up to 1.77 GPa using muon spin rota tion ($\\mu$SR) experiments. The ambient pressure $\\mu$SR measurements de monstrate a fully gapped $s$-wave superconducting state in the bulk. The o bservation of $s$-wave superconductivity in $\\alpha$-PdBi$_2$ is quite cr ucial in search for Majorana fermions as it is theoretically predicted tha t in presence of an in-plane magnetic field\, the Majorana zero mode can b e realized utilizing the coupling of an $s$-wave superconductor with a mat erial exhibiting Rashba states. Further\, AC magnetic susceptibility and $ \\mu$SR measurements under hydrostatic pressure manifest a continuous supp ression of $T_c$ with increasing pressure. We observed a considerable decr ease of superfluid density by ~20% upon application of external pressure. Remarkably\, the superfluid density follows a linear relation with $T_c$ w hich was found before in some unconventional topological superconductors a nd hole doped cuprates. This finding indicates a possible crossover from B ose-Einstein to Bardeen-Cooper-Schrieffer like condensation in $\\alpha$-P dBi$_2$.\n\nReference\nDebarchan Das\, R. Gupta\, C. Baines\, H. Luetkens\ , D. Kaczorowski\, Z. Guguchia\, and R. Khasanov\, Phys. Rev. Lett. 127\, 217002 (2022).\n\nhttps://indico.stfc.ac.uk/event/53/contributions/3650/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3650/ END:VEVENT BEGIN:VEVENT SUMMARY:Is the Abrikosov’s vortex-model still valid in nematic supercond uctors? DTSTART;VALUE=DATE-TIME:20220901T104000Z DTEND;VALUE=DATE-TIME:20220901T110000Z DTSTAMP;VALUE=DATE-TIME:20220826T100913Z UID:indico-contribution-53-3683@indico.stfc.ac.uk DESCRIPTION:Speakers: Gianrico LAMURA (CNR-SPIN)\nSpontaneous rotational-s ymmetry breaking (RSB) in the amplitude of the superconducting gap is a ne cessary condition for “nematic” superconductivity. This was evidenced in the topological superconductor Cu$_x$Bi$_2$Se$_3$ where\, despite the t hreefold symmetry of its lattice\, a twofold symmetry of electronic proper ties emerged from nuclear magnetic resonance$^1$\, transport$^2$\, and spe cific-heat$^3$ measurements\, when the applied magnetic field is rotated i n the Se planes. This is also the case of CaSn$_3$ semimetal with the cubi c AuCu$_3$-type structure: we prove a spontaneous RSB below Tc$^4$ by magn etotransport- and muon-spectroscopy (μSR) measurements.\nParticularly mea ningful are the transverse-field (TF)- μSR results in the mixed supercond ucting phase of CaSn$_3$\, where the muon-depolarization rate depends on t he magnetic field direction (here\, applied along the [110] or [001] crys tal directions). The absence of any additional muon depolarization along [ 110] suggests that an *unconventional vortex lattice* (VL) sets in. Conver sely\, in the [001] case\, a VL encompassing at least 52% of the sample vo lume indicates the bulk nature of superconductivity.\nSimilarly\, by scann ing tunnelling spectroscopy in Cu$_x$Bi$_2$Se$_3$\, vortices exhibit an el liptical shape within stretched VLs for applied fields H orthogonal to the Se planes\, whereas “no obvious in-plane vortices” could be observed for H parallel to the Se layers$^5$.\nSuch evidence and our current experi mental results on CaSn$_3$ seriously question the pertinence of the conven tional Abrikosov model to the superconducting mixed state of nematic super conductors since multi-component order parameter superconductors may exhib it unusual vortex structures (fractional and/or non-axial vortices)$^6$. \ nFinally\, the superfluid density in the (001) planes\, extracted from TF -µSR data\, shows a fully gapped low-temperature behaviour\, with $\\Delt a$(0)=0.61(7) meV. Additional zero-field μSR results indicate that the s uperconducting state is time-reversal invariant. This fact and the RSB in a fully-gapped superconductor suggest CaSn$_3$ as *nematic superconductor with an unconventional pairing state in a multidimensional representation* .\n$^1$https://doi.org/10.1038/nphys3781\n$^2$https://doi.org/10.1038/s414 67-019-14126-w\n$^3$https://doi.org/10.1038/nphys3907\n$^4$https://doi.org /10.1103/PhysRevB.105.094508\n$^5$https://doi.org/10.1103/PhysRevX.8.04102 4\n$^6$https://doi.org/10.1103/RevModPhys.63.239\n\nhttps://indico.stfc.ac .uk/event/53/contributions/3683/ LOCATION:Science and Technology Campus\, University of Parma URL:https://indico.stfc.ac.uk/event/53/contributions/3683/ END:VEVENT END:VCALENDAR