75 Result(s)
within
K Nishiyama
Atomic, Molecular, Optical and Plasma Physics
Surfaces and Interfaces, Thin Films
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Article
New precise measurement of muonium hyperfine structure interval at J-PARC
MuSEUM is an international collaboration aiming at a new precise measurement of the muonium hyperfine structure at J-PARC (Japan Proton Accelerator Research Complex). Utilizing its intense pulsed muon beam, we...
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Article
New muonium HFS measurements at J-PARC/MUSE
At the Muon Science Facility (MUSE) of J-PARC (Japan Proton Accelerator Research Complex), the MuSEUM collaboration is planing new measurements of the ground state hyperfine structure (HFS) of muonium both at ...
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Article
Open AccessUltra slow muon microscopy by laser resonant ionization at J-PARC, MUSE
As one of the principal muon beam line at the J-PARC muon facility (MUSE), we are now constructing a Muon beam line (U-Line), which consists of a large acceptance solenoid made of mineral insulation cables (MI...
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Article
Dai Omega, a Drastic Upgrading of the Surface Muon Channel Using a Large Solid Angle Axial Focusing Superconducting System
An axial focusing surface muon channel, Dai Omega, is under construction. This channel will be installed at KEK-MSL in the summer of 2001. It uses four large aperture superconducting coils for axial focusing t...
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Article
Recent Progress in the Study on Muonium Centers in Semiconductors
The electronic structures and the locations of muonum centers (Mu) were investigated in single crystalline ZnO. Mu centers with extremely small hyperfine parameters have been observed below 40 K. It is inferre...
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Article
The Muon Science Facility at the JKJ Project
The muon science facility is one of the experimental arenas of the JKJ project, which was recently approved for construction in a period from 2001 to 2006, as well as neutron science, particle and nuclear phys...
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Article
μSR Study of the Unusual Magnetic Ordering in the Frustrated Antiferromagnet Zn(Cr x Ga1−x )2O4
μSR spectra on the spin frustrating spinel antiferromagnet Zn(Cr x Ga1−x )2O4 (x=0.9,1.0) have been measured. For x=1.0 compound, both the relaxation rate and the...
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Article
Theoretical Investigation of Muon and Muonium Trap** and Hyperfine Interactions in the Chemical Ferromagnet p-NPNN (β-phase)
The trap** sites for muon and muonium in β-phase ferromagnetic p-NPNN have been determined by the first-principles Unrestricted Hartree–Fock procedure. Four trap** sites are found for the muon near the two...
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Article
Shallow-Donor Hydrogen-Like Impurities in ZnO Studied by MuSR
Two species of Mu centers with extremely small hyperfine parameters have been observed in single crystalline ZnO below 40 K. Both Mu centers have an axial symmetric hyperfine structure along with the [0001] ax...
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Article
μ–H Interaction in Hydrogen Bonding Systems
Muon spin rotation (μSR) experiments were performed on single crystal samples of KH2PO4(KDP) and KD2PO4(dKDP) to study the dynamics of hydrogen in hydrogen bonding systems. At low temperature, the nuclear dipole ...
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Article
Determination of Easy Axis in a Chemical Ferromagnet, 4-(p-Chlorobenzylideneamino)–TEMPO (TEMPO=2,2,6,6-Tetramethylpiperidin-1-Oxyl)
The trap** sites for muon and muonium in ferromagnetic p-Cl–Ph–CH=N–TEMPO [(4-(p-chlorobenzylideneamino)–TEMPO (TEMPO = 2,6,6-tetramethyl-piperidin-1-yloxyl)] and the hyperfine interaction tensors for these ...
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Article
Multiple Phase Transitions in CuO Studied by μSR
Precise measurements of the local magnetic field at muon sites in CuO were performed. The temperature dependence of the local field including spatial orientation was obtained in the ordered state. Not only zer...
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Article
Muonium quadrupole interaction in ferroelectric substances KDP and KHCO3
The muonium quadrupole interaction is determined in KDP and KHCO3. Using single crystal the field gradient tensor was obtained from muonium precession under the transverse field at room temperature. The muonium s...
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Article
Muon spin relaxation in spin gap state of BaVS3
Positive muon spin relaxation measurements were performed on a spin-1/2 system BaVS3, which shows a metal-insulator transition at TMI= 70 K. We found a marked muon-spin depolarization below TX= 30 K without appre...
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Article
Spin dynamics of the diluted antiferromagnet FexMg1-xTiO3 by muon spin relaxation method
The diluted antiferromanget FexMg1-xTiO3 which transforms from the antiferro-magnetic (AF) system to the cluster-glass (CG) one with dilution is investigated by muon spin relaxation measurements. We compare the c...
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Article
Spin dynamics of diluted antiferromagnets MnxMg1-xTiO3 by μSR method
The diluted antiferromagnet MnxMg1-xTiO3 transforms from the antiferromagnet (AF) to the spin-glass (SG) system at x ∼ 0.6. In order to study the microscopic nature of spin dynamics and ordering, we performed muo...
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Article
Photon recycling transport in bulk GaAs probed by μSR with laser irradiation
A newly developed μSR method combined with a tunable, high power and sharply pulsed laser was applied to GaAs. Anomalous transport phenomena of the photo excited effects into bulk crystal were observed, given ...
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Article
MuSR/μ+SR studies in KDP and DKDP
The temperature dependence of muon interactions has been studied in ferroelectric KDP ( H2KPO4) and DKDP ( D2KPO4) using conventional μSR and muon spin resonance spectroscopy. In longitudinal field measurements, ...
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Article
μSR study of the magnetic ordering in Ce1-xLaxRu2Si2
Zero‐field μSR measurements have been carried out in the paramagnetic and magnetically ordered states of the heavy fermion alloys: Ce1-xLaxRu2Si2 (x=0.05,0.13,0.25). In Ce1-xLaxRu2Si2 system, TK drastically decre...
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Article
Theory of hyperfine interactions associated with the negative muon in lanthanum copper oxide high Tc system
We have carried out first‐principles Unrestricted Hartree–Fock Cluster investigations to demonstrate that the Auger holes produced by the entry of μ- into the oxygen ions in La_2CuO_4 lead to stable O-μ- centers ...
