A5077422759- Muon and positron interactions and applications
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Advancements in Battery Materials
- Multiferroics and related materials
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Atomic and Molecular Physics
- Advanced Battery Materials and Technologies
- Inorganic Fluorides and Related Compounds
- Solid-state spectroscopy and crystallography
- Particle physics theoretical and experimental studies
- Ammonia Synthesis and Nitrogen Reduction
- Plasma Diagnostics and Applications
- High-pressure geophysics and materials
- High-Energy Particle Collisions Research
- Magnetic Properties and Synthesis of Ferrites
- Atomic and Subatomic Physics Research
- Fusion materials and technologies
- Graphene research and applications
- Microwave Dielectric Ceramics Synthesis
- X-ray Diffraction in Crystallography
High Energy Accelerator Research Organization
2013-2024
Japan Proton Accelerator Research Complex
2011-2024
Institute of Materials Structure Science
2005-2021
Toyota Central Research and Development Laboratories (Japan)
2006-2017
University of Yamanashi
1997-2015
Japan Atomic Energy Agency
2011-2015
Takeda (Japan)
2000-2015
RIKEN Nishina Center
2010-2015
Toyota Motor Corporation (Switzerland)
2009-2011
The University of Tokyo
2010-2011
The diffusion coefficient of Li+ ions (D(Li)) in the battery material LixCoO2 has been investigated by muon-spin relaxation (mu+SR). Based on experiments zero and weak longitudinal fields at temperatures up to 400 K, we determined fluctuation rate (nu) muons due their interaction with nuclear moments. Combined susceptibility data electrostatic potential calculations, clear ion was detected above approximately 150 K. D(Li) estimated from nu very good agreement predictions first-principles...
The antiferromagnetic (AF) nature of the normal spinel ${\mathrm{Co}}_{3}{\mathrm{O}}_{4}$ with N\'eel temperature $({T}_{\mathrm{N}})=30\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ was investigated by means positive muon spin rotation and relaxation $({\ensuremath{\mu}}^{+}\mathrm{SR})$ techniques using a polycrystalline sample. Clear precession signals due to quasistatic long-range AF order were found in zero-field ${\ensuremath{\mu}}^{+}\mathrm{SR}$ spectra below ${T}_{\mathrm{N}}$. consist two...
In order to elucidate the magnetism and Li diffusion in LiFePO${}_{4}$, we have measured muon-spin rotation relaxation (${\ensuremath{\mu}}^{+}$SR) spectra for polycrystalline LiFePO${}_{4}$ sample temperature range between 1.8 500 K. Below ${T}_{\mathrm{N}}\ensuremath{\sim}52$ K, two oscillatory signals together with one fast signal were clearly found zero-field (ZF) ${\ensuremath{\mu}}^{+}$SR spectrum. The three are reasonably explained using an antiferromagnetic (AF) spin structure...
A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It near-ideal two-body system for precision test bound-state theory fundamental symmetries. The MuSEUM collaboration performed new measurement the muonium ground-state hyperfine structure at J-PARC using high-intensity pulsed beam high-rate capable positron counter. resonance transition was successfully observed near-zero magnetic field, interval $ν_{\text{HFS}}$ = 4.463302(4) GHz obtained with relative...
The magnetism of ${\mathrm{Li}}_{x}{\mathrm{CoO}}_{2}$ (LCO), which has a similar structure to ${\mathrm{Na}}_{x}{\mathrm{CoO}}_{2}$ (NCO), been investigated by muon-spin spectroscopy and susceptibility measurements using samples with $x=0.1--1$ prepared an electrochemical reaction. In the $x$ range below 0.75, LCO was found be Pauli paramagnetic down 1.8 K, suggesting intermediate- or weak-coupling regime, although disordered local moments, volume fractions $\ensuremath{\sim}20%$, appear at...
In order to elucidate the effect of Ni ions in Li layer on magnetism and diffusion ${\text{LiNiO}}_{2}$, we have measured muon-spin rotation relaxation $({\ensuremath{\mu}}^{+}\text{SR})$ spectra for polycrystalline ${\text{Li}}_{1\ensuremath{-}x}{\text{Ni}}_{1+x}{\text{O}}_{2}$ samples with $x=0.02$, 0.03, 0.15. Weak transverse-field-${\ensuremath{\mu}}^{+}\text{SR}$ measurements demonstrated existence a bulk ferromagnetic transition at ${T}_{\text{m}}=48(6)\text{ }\text{K}$ $x=0.03$ sample...
In order to study the diffusive nature of lithium transition-metal phospho-olivines, we measured muon-spin relaxation (${\ensuremath{\mu}}^{+}$SR) spectra for polycrystalline Li$M$PO${}_{4}$ samples with $M=\text{Mn}$, Fe, Co, or Ni in temperature range between 50 and 500 K. The ${\ensuremath{\mu}}^{+}$SR under zero applied field are strongly affected by magnetic moments 3$d$ electrons ${M}^{2+}$ ions so that, LiMnPO${}_{4}$, it was difficult detect change caused diffusion due large...
The muon science facility (MUSE) is located in the Materials and Life Science Facility (MLF), which a building integrated to include both neutron programs. For Phase 1, we succeeded installing one super conducting decay/surface beamline, so called D-line, with modest-acceptance pion injector of about 45 mSr summer 2008. In November 2009, by iterative beam tuning developing new beamline elements such as larger separator, surface muons (μ +) extraction rate was significantly increased up 1.8 ×...
The quasi-one-dimensional (Q1D) cobalt oxides A(N + 2)Co(n 1)O(3n 3) (A = Ca, Sr, and Ba, n 1 - infinity) were investigated by muon-spin spectroscopy under applied pressures of up to 1.1 GPa. relationship between the onset Néel temperature T(on)(N) interchain distance (d(ic)), which increases monotonically with n, is well fitted formula T(N)/T(N,0) (1 d(ic)/d(ic,o)(beta), here for approximately 100 K Ca(3)Co(2)O(6) (n 1) 15 BaCoCoO(3) infinity at ambient P. d(ic) curve also predicts a large...
In order to elucidate the magnetic nature of lithium chromium dioxide ${\text{LiCrO}}_{2}$, in which ${\text{Cr}}^{3+}$ ions form a two-dimensional triangular lattice ${\text{CrO}}_{2}$ plane, we have performed positive muon-spin rotation and relaxation $({\ensuremath{\mu}}^{+}\text{SR})$ experiment using powder sample temperature range 1.7--155 K. Weak-transverse-field measurements indicated existence bulk antiferromagnetic (AF) transition at ${T}_{N}=61.2\text{ }\text{K}$. Below ${T}_{N}$,...
The microscopic magnetic nature of ${\text{Ca}}_{1\ensuremath{-}x}{\text{Na}}_{x}{\text{V}}_{2}{\text{O}}_{4}$ with $0\ensuremath{\le}x\ensuremath{\le}1$ has been investigated by a positive muon-spin spectroscopy $({\ensuremath{\mu}}^{+}\text{SR})$ using powder samples for temperatures down to 1.8 K. Static antiferromagnetic (AF) order is observed the metallic compounds $x\ensuremath{\ge}9.3/12$ as well ${\text{NaV}}_{2}{\text{O}}_{4}$ and insulating ${\text{CaV}}_{2}{\text{O}}_{4}$. A...
The nature of the magnetic transition half-filled triangular antiferromagnet ${\mathrm{Ag}}_{2}{\mathrm{NiO}}_{2}$ with ${T}_{\mathrm{N}}=56\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ was studied positive muon-spin-rotation and relaxation $({\ensuremath{\mu}}^{+}\mathrm{SR})$ spectroscopy. Zero field ${\ensuremath{\mu}}^{+}\mathrm{SR}$ measurements indicate existence a static internal at temperatures below ${T}_{\mathrm{N}}$. Two components slightly different precession frequencies wide...
As one of the principal muon beam line at J-PARC facility (MUSE), we are now constructing a Muon (U-Line), which consists large acceptance solenoid made mineral insulation cables (MIC), superconducting curved transport and axial focusing magnets. There, can extract 2 × 108/s surface muons towards hot tungsten target. At U-Line, establishing new type microscopy; technique with use intense ultra-slow source generated by resonant ionization thermal Muonium (designated as Mu; consisting μ + an e...
In spite of numerous experimental and theoretical reports on ${\text{LiNiO}}_{2}$, no consistent picture has emerged the nature its ground state. We have investigated ${\text{Li}}_{x}{\text{NiO}}_{2}$ system $(0.1\ensuremath{\le}x\ensuremath{\le}1)$ by means muon-spin spectroscopy susceptibility to gain further insight from effects varying magnetic ion concentration. Static order, most likely be incommensurate spatial lattice period, was found for $x\ensuremath{\ge}0.6$ at low temperatures...
We present muon-spin-rotation measurements on polycrystalline samples of the complete family antiferromagnetic (AF) zigzag chain compounds, ${\text{Na}}_{x}{\text{Ca}}_{1\ensuremath{-}x}{\text{V}}_{2}{\text{O}}_{4}$. In this family, we explore magnetic properties from metallic ${\text{NaV}}_{2}{\text{O}}_{4}$ to insulating ${\text{CaV}}_{2}{\text{O}}_{4}$. find a critical ${x}_{c}(\ensuremath{\sim}0.833)$ which separates low and high Na-concentration-dependent transition temperature its...
The magnetic nature of the spinel antiferromagnet $\mathrm{Li}[{\mathrm{Li}}_{x}{\mathrm{Mn}}_{2\ensuremath{-}x}]{\mathrm{O}}_{4}$ with $x=0--0.15$ has been studied muon-spin rotation and relaxation $({\ensuremath{\mu}}^{+}\mathrm{SR})$ spectroscopy. Both weak-transverse-field zero-field ${\ensuremath{\mu}}^{+}$SR measurements indicate that whole sample enters into a static disordered phase below ${T}_{\mathrm{N}}$ for all samples measured;...
Using quasielastic neutron scattering (QENS), we have investigated a self-diffusive behavior of Li${}^{+}$ ions for both $^{7}\mathrm{Li}$Mn${}_{2}$O${}_{4}$ and $^{7}\mathrm{Li}$${}_{1.1}$Mn${}_{1.9}$O${}_{4}$ spinels. In addition, carried out elastic inelastic measurements using the same samples, to study interrelationship between self-diffusion, magnetism, charge distribution in lattice. From QENS results, self-diffusion was observable above 280 K, coefficient (${D}_{s}^{\mathrm{Li}}$)...
The muon science facility (MUSE), along with the neutron, hadron, and neutrino facilities, is one of experimental areas J-PARC project. MUSE located in Materials Life Science Facility (MLF), which a building integrated to include both neutron programs. Since autumn 2008, users operation effective making use pulsed beam particularly at D-Line. Unfortunately, suffered severe damages from earthquake on March 11, 2011, so-called "Higashi-Nippon Dai-Shinsai". We managed have stable...
Cation-ordered Li[Ni1/2Mn3/2]O4 with a P4332 space group (CO-LNMO) and "cation-disordered" (CDO) LNMO are thought to be the state-of-the-art materials for lithium-ion batteries. However, in contrast CO-LNMO, crystal structure electrochemical reaction scheme of CDO-LNMO not fully understood. We have measured muon-spin rotation relaxation (μSR) spectra samples both CO-LNMO CDO-LNMO, particular at their magnetic transition temperatures (TC) below 130 K. The weak transverse field (wTF) μSR...
By means of muon-spin spectroscopy, we have found that K0.49CoO2 crystals undergo successive magnetic transitions from a high-T paramagnetic state to ordered below 60 K and then second 16 K, even though is metallic at least down 4 K. An isotropic behavior wide internal-field distributions suggest the formation commensurate helical spin density wave (SDW) while linear SDW likely exist above It was also exhibits further transition 150 presumably due change in Co ions. Since dependence similar...
Thanks to the unique power of muon-spin spectroscopy, we found that quasi-one-dimensional Co-Rh oxides ${A}_{n+2}\mathrm{Co}{\mathrm{Rh}}_{n}{\mathrm{O}}_{3n+3}$ ($A=\mathrm{Ca},\mathrm{Sr}$; $n=1$, 2, and 3) exhibit a two-dimensional antiferromagnetic transition ranges from ${T}_{N}^{\text{on}}=185\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ for $n=1$ $125\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ $n=3$ with width $(\ensuremath{\Delta}T)$ about $80\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The variation...
In order to elucidate the magnetic nature of ${\mathrm{K}}_{x}\mathrm{Co}{\mathrm{O}}_{2}$ in vicinity $x=0.5$, we have measured positive muon spin rotation and relaxation $({\ensuremath{\mu}}^{+}\mathrm{SR})$ spectra using polycrystalline samples $x=0.6$, $4∕7$, 0.5 temperature range between 1.8 $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. A zero-field spectrum suggests existence localized but disordered moments below $20\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ for $x=0.6$ sample, whereas...