1990 Fiscal Year Final Research Report Summary
Soft X-Ray Spectroscopic Studies of Mixed Valence 4f Electronic States in Rare Earth Compounds
| Project/Area Number |
01540264
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Utsunomiya University |
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Principal Investigator |
NAKAI Shun-ichi Utsunomiya University, Faculty of Engineering, Professor, 工学部, 教授 (70081429)
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| Co-Investigator(Kenkyū-buntansha) |
MITSUISHI Tsutomu Utsunomiya University, Faculty of Engineering, Assistant, 工学部, 助手 (00008054)
SUGIURA Chikara Utsunomiya University, Faculty of Engineering Professor, 工学部, 教授 (20006406)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Soft X-Ray Spectroscopy / Rare-Earth Compounds / Mixed Valence |
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| Research Abstract |
(1) Measurement of polarization dependency in Ce 3d absorption spectra of CeRh_3B_2. CeRh_3B_2 is known to be a ferromagnet with a hexagonal crystal structure, and many studies have been carried out on the compounds since it has a high Curie temperature, i. e., T_o =112K. It is also known as a mixed valence material with the number of 4f electrons n_f in the ground state as n_f = 0.85-0.90, from the result of photoemission spectroscopy. The Ce atoms in CeRh_3B_2 form linear chains along the c-axis, and the interatomic Ce-Ce distance in this direction is much smaller than that in the c-plane. So, a difference in the Ce 3d x-ray absorption spectra between polarization parallel and perpendicular to the hexagonal c-axis of CeRh_3B_2 is expected. The measurement is held this April at KEK-PF.
(2) New development of parallel plate avalanche chamber (PPAC) for detection of soft x-ray. In the caseo f bulk crystals, the absorption spectra were measured by total electron yield method. The ejected photoelectron is very sensitive to the surface condition. On the other hand, the fluorescent x-ray is very useful to detect the bulk materials. In order to detect the fluorescent x-ray, gas flow proportional chamber is used. For this purpose, the low pressure parallel plate avalanche chamber is designed and now test operated.
(3) Electron energy loss spectrometer. It is well known that the electron energy loss spectra (EELS) provide the same information as the soft x-ray absorption spectra (XAS). The reflection type energy loss spectrometer is a useful research tool for use in solid state physics. Until now, the electrostatic double focusing energy analyzer was made and the electron gun and lens systems are designed. A project is in progress.
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