Solid State Physics Research with Pulsed Muons

在本基金的帮助下，在位于KEK.1的东京大学介子科学实验室的脉冲介子设备上，用mu SR方法进行了固体物理研究，取得了以下研究成果。重费米子系统Muroran工业研究所的研究组（S.Murayama, et.al）和大阪大学的研究组（T.Miyako, et.al）分别成功地观察到了CeRuRhSi和CeLaRuSi中的SDW（自旋密度波）现象。富井大学（Fukui University）课题组（M.Mekata, et al）在fe_2上研究了自旋动力学，Ochanomizu大学（A.Ito, et al）在FeMnTiO_3上研究了自旋动力学。固体氢中的μ子分子东京工业大学小组（N.Nishida等）在固体H_2和D_24中观察到（H_2mu^+）分子的存在和特征自旋弛豫。山梨大学的研究小组（E.Torikai, et.al.）在有限的温度范围内观察到Sb中的mu^+的顺磁状态。光照下Si中的μ子态RIKEN小组（R.Kadono等）通过有光照和无光照的mu SR方法揭示了Si中μ子键态的存在，这可能解释了氢钝化的一个基本过程。在500 MeV质子束下，用热钨表面产生的热muonium的激光共振电离方法成功地产生了eV-keV慢mu^+。在500A Au的薄层上观察到mu SR信号。

With the aid of the present Grant, the following research outputs have been obtained on solid state physics research with mu SR methods at the pulsed muon facility of the Meson Science Laboratory of the University of Tokyo located at KEK.1. Heavy Fermion SystemBoth rhe Muroran Institute of Technology group (S.Murayama, et.al.) and the Osaka University group (T.Miyako, et.al.) have successfully observed SDW (spin density wave) phenomenon in CeRuRhSi and CeLaRuSi, respectively.2. Flustrating Magnetic SystemSpin dynamics in flustrating magnetic system has been probed by the Fukui University group (M.Mekata, et.al.) on FeI_2, and by the Ochanomizu University group (A.Ito, et.al.) on FeMnTiO_3, etc..3. Muon Molecule in Solid HydrogenThe Tokyo Institute of Technology group (N.Nishida, et.al.) has observed an existence as well as a characteristic spin relaxation of (H_2mu^+) molecule in solid H_2 and D_24. Muon State in Semi-metallic SbThe Yamanashi University group (E.Torikai, et.al.) has observed a paramagnetic state of mu^+ in Sb at a limited temperature range.5. Muon State in Si under IlluminationThe RIKEN group (R.Kadono, et.al.) has revealed an existence of the muon bonding state in Si by the mu SR method with and without illumination, which may explain a fundamental process of hydrogen passivation.6. Generation of Ultra-slow mu^+ beamSuccessfull generation was made for eV-keV slow mu^+ by laser resonant ionization method of thermal muonium produced from hot tungsten surface placed at 500 MeV proton beam. The mu SR signal was seen from thin layer of 500A Au.