| Project/Area Number |
10640299
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KOTANI Akio Institute for Solid State Physics, The University of Tokyo, Professor, 物性研究所, 教授 (90029504)
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| Co-Investigator(Kenkyū-buntansha) |
OGASAWARA Haruhiko Institute for Solid State Physics, The University of Tokyo, Research Associate, 物性研究所, 助手 (80262161)
OKADA Kozo Okayama University, Faculty of Science, Associate Professor, 物理学部, 助教授 (70194355)
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| Project Period (FY) |
1998 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | spectroscopy / rare-earth compounds / transtion-metal compounds / cluster model / polarization-dependence / charge transfer / electron correlation / magnetic circular dichroism / 共鳴X線発光 / 干渉効果 / 電気四重極子励起 / 配置間相互作用 / 内殻正孔 / 遍歴性 / 局在性 / 円偏光二色性 |
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| Research Abstract |
Among the magnetic materials known so far, CeSb has the most complex phase diagram as a function of temperature and magnetic field. The complex magnetic phase diagram is know as the devil's staircase. Generally, the series of CeX (X=P, As, Bi, Sb) have complex magnetic phase diagrams in different degree, which suggests that there is a common mechanism for the devil's staircase observed in CeX. A characteristic feature of CeX is smallness of carriers. The carriers of CeX consist of holes at the Γ point and electrons at the X points. Under this situation, a new type of scattering processes from holes to electrons and vice versa accompanied by spin exchange with f-spins. This process may be called off-diagonal exchange in contrast to the usual exchanges where the scattering are within a band. The momentum transfer associated with his off-diagonal exchange corresponds to the antiferromagnetic wave vector, favoring antiferromagnetic RKKY interaction among the f spins. On the other hand, the ordinary exchanges favor ferromagnetic coupling in the low carrier limit. In this project, we have shown that the frustration between the RKKY interactions originated from these two types of exchange mechanisms is the basic mechanism for the devil's staircase in CeX by using a simple/
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