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Zn
probed by muon spin relaxationHigemoto, Wataru; Ito, Takashi; Ninomiya, Kazuhiko; Onimaru, Takahiro*; Matsumoto, Keisuke*; Takabatake, Toshiro*
Physical Review B, 85(23), p.235152_1 - 235152_4, 2012/06
Times Cited Count：4 Percentile：19.65(Materials Science, Multidisciplinary)We performed muon spin rotation and relaxation measurements (
SR) in caged structural heavy fermion system PrIrZn to elucidate magnetic and superconducting properties. Temperature independent SR spectra were observed below 1K, indicating that the phase transition at 0.11K is non-magnetic origin, most probably pure quadrupole ordering. In the superconducting phase, no sign of unconventional superconductivity, like a broken time reversal symmetry superconductivity, is seen below 
=0.05K. Moreover, we have observed spontaneous muon spin precession in a zero field in the paramagnetic phase below 15K, suggesting a novel coupling between 
Pr nuclei and muon realize in PrIrZn.
diffusion in cubic 
-electron compounds observed by high transverse field SRIto, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Heffner, R. H.; Aoki, Yuji*; Suzuki, Hiroyuki*; Onimaru, Takahiro*; Tanida, Hiroshi*; Takagi, Shigeru*
Journal of Physics; Conference Series, 225, p.012021_1 - 012021_6, 2010/06
Times Cited Count：2 Percentile：66.93(Physics, Applied)The diffusion of positive muon in condensed matter has been investigated for many years by using spin rotation/relaxation (SR) technique. The SR studies have provided deep insight into quantum diffusion at low temperatures as well as hopping process at high temperatures, which are closely related to hydrogen dynamics in the dilute limit. We here report transverse field (TF) SR studies of the diffusion in cubic -electron compounds PrPb
and SmAgIn. The site splits into two magnetically labeled sites when high TF is applied to single-crystalline specimens along the [001] direction. The SR lines show drastic variation according to the motion between the magnetically labeled sites. From detailed analysis of the SR lines, we deduced hopping parameters for both compounds.
site in PrPb; Interplay between localized electrons and an interstitial charged particleIto, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Heffner, R. H.; Aoki, Yuji*; Amato, A.*; Onimaru, Takahiro*; Suzuki, Hiroyuki*
Physical Review Letters, 102(9), p.096403_1 - 096403_4, 2009/03
Times Cited Count：14 Percentile：62.72(Physics, Multidisciplinary) in paraquadrupolar stateIto, Takashi; Higemoto, Wataru; Oishi, Kazuki; Heffner, R. H.; Nishida, Nobuhiko*; Aoki, Yuji*; Onimaru, Takahiro*; Suzuki, Hiroyuki*
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.743 - 745, 2007/03
PrPb exhibits antiferroquadrupole ordering at T
= 0.4 K. In the ordering phase, incommensurate structure of quadruple was found from recent experimental study and much attention is paid to this compound. We performed muon spin rotation and relaxation measurements on a single crystalline sample of PrPb. A quite anisotropic contact-coupling constant was extracted from the muon Knight shift, possibly concerned with nonspherical distribution of 4-electron at low temperature. The contact and dipole coupling constants are of comparable magnitudes, suggesting significance of strong hybridization between the 
electrons of Pr and the conduction electrons for incommensurate structure.
COyama, Kenji*; Kaneko, Koji; Onimaru, Takahiro*; Tobo, Aya*; Ishimoto, Kenichi*; Onodera, Hideya*; Yamaguchi, Yasuo*
Journal of the Physical Society of Japan, 72(12), p.3303 - 3304, 2003/12
Times Cited Count：6 Percentile：43(Physics, Multidisciplinary)no abstracts in English
SR study on multipolar ordering in PrPb, 2Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki; Heffner, R. H.; Nishida, Nobuhiko*; Aoki, Yuji*; Onimaru, Takahiro*; Suzuki, Hiroyuki*
no journal, ,
no abstracts in English
Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Aoki, Yuji*; Onimaru, Takahiro*; Suzuki, Hiroyuki*
no journal, ,
no abstracts in English
-Pr in PrPbIto, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Heffner, R. H.; Aoki, Yuji*; Amato, A.*; Onimaru, Takahiro*; Suzuki, Hiroyuki*
no journal, ,
An isolated few-spin system including a spin 
is usually unlikely to be realized in metal. Contrary to the expectation, we actually found an isolated three-spin system Pr--Pr in a rare-earth intermetallic compound PrPb. This system results in spin precession with six frequencies at regular intervals. Such harmonic frequencies cannot be obtained only from dipolar interactions between and bare Pr nuclear spins 
. Extremely anisotropic enhancement of the - coupling is required. This enhancement can be explained by mechanism of the Pr hyperfine-enhanced nuclear magnetism and -induced perturbation on 4f-electronic state of two Pr ions next to the .
SR studies on PrRhZnHigemoto, Wataru; Ito, Takashi; Nagasawa, Naohiro*; Onimaru, Takahiro*; Takabatake, Toshiro*
no journal, ,
In caged structural compound PrRhZn, superconductivity and other unknown phase transition occur at the same temperature 0.06K. This phase transition is speculated as quadrupole phase transition. However, no any microscopic study is carried out up to now and detail of the phase transition is not known at all. We have studied quadrupole ordering and superconductivity in PrRhZn by using muon spin relaxation method at J-PARC muon science facility. As a result, we have not observed any significant change of the signal above and below phase transition temperature. This fact indicate the no magnetic phase transition occur and support the quadrupole phase transition. In addition, no trace of an unconventional superconductivity was detected in our measurements. In the presentation, we will mention detail of the measurements.
SR study on PrIrZn under magnetic fieldHigemoto, Wataru; Okazawa, Takeshi; Oshima, Kohei*; Ito, Takashi; Robert, S.*; Matsumoto, Keisuke*; Onimaru, Takahiro*
no journal, ,
no abstracts in English
