1988 Fiscal Year Final Research Report Summary

Study of paramagnetic phase of metallic magnet by means of microscopic methods

Research Project

Project/Area Number	62540228
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	固体物性
Research Institution	Saitama University
Principal Investigator	MOTOYA Kiyoichiro Faculty of Science, Saitama University Associate Professor, 理学部, 助教授 (60114683)
Project Period (FY)	1987 – 1988
Keywords	Magnetism / Metals / Neutron Scattering / Nuclear Magnetic Resonance / 核磁気共鳴 / 電子相関
Research Abstract	Elastic and inelastic neutron scattering measurements have been made on a series of pseudobinary intermetallic compounds Y(Mn_<1-x>Al_x)_2. Long range antiferronagnetic order below T_N - 100K in YMn_2 has been shown to collapse by substitution of only 5% of the manganese atoms by aluminum atoms. In these compounds, a spin glass transition has been clearly indicated by a change in the energy width of the scattered neutron spectrum, as well as by the onset of field hysteresis in susceptibility measurements. In the compound with x = 0.10, the amplitude of spin fluctuations S does not change appreciably with temperature, whereas in YMn_2 it drops by more than 30% at T_N and then increases gradually with increasing temperature. A considerable degree of spatial correlations of spin fluctuations persists up to at least 760K, which is similar to the behavior observed in YMn_2 but quite different from the characteristics of simple localized electron magnets.