| Project/Area Number |
10304059
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | The University of Tokyo |
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Principal Investigator |
OHTA Toshiaki School of Science, Dept.of Chemistry, The University of Tokyo, Professor, 大学院・理学系研究科, 教授 (80011675)
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| Co-Investigator(Kenkyū-buntansha) |
AMEMIYA Kenta School of Science, Dept.of Chemistry, The University of Tokyo, Research Associate, 大学院・理学系研究科, 助手 (80313196)
KONDOH Hiroshi School of Science, Dept.of Chemistry, The University of Tokyo, Lecturer, 大学院・理学系研究科, 講師 (80302800)
YOKOYAMA Toshihiko School of Science, Dept.of Chemistry, The University of Tokyo, Associate Professor, 大学院・理学系研究科, 助教授 (20200917)
廉 罕雄 東京大学, 大学院・理学系研究科, 助手 (50282504)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥33,400,000 (Direct Cost: ¥33,400,000)
Fiscal Year 2000: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1999: ¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1998: ¥23,200,000 (Direct Cost: ¥23,200,000)
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| Keywords | XMCD / XAFS / Surface magnetism / Magnetic thin film / molecular adsorbate / 磁気円偏光二色性(XMCD) / 磁気異方性 |
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| Research Abstract |
The purpose of this research proposal is to investigate the magnetic interaction between magnetic thin films and adsorbed molecules by use of the X-ray Magnetic Circular Dichroism (XMCD) method. In this year, we have constructed a new soft x-ray beamline in the Photon Factory, whose performance is much higher than that we used before. Thus, it turned out that even very weak XMCD signal can be detected with the new beamline. We have carried out following three subjects.
(1) Co L-MCD and O K-MCD study of O and CO adsorbed Co thin films. The magnetism induced by O adsorbate is ferromagnetic, but that induced by CO is antiferromagnetic to the substrate Co magnetism. This result suggests that the adsorption site sensitively affect the magnetic behavior.
(2) Ni L-MCD and O K-MCD of CO adsorbed Ni thin films. It is known that the magnetic easy axis is in plane in the Ni thickness of less than 10 ML, and perpendicular in the range of 10-50 ML, and again in plane above 50 ML.It was revealed that CO adsorption extends the region of perpendicular magnetic anisotropy (PMA) to 6 ML-50ML.Furthermore, the induced magnetic moment of CO is ferromagnetic at PMA, and antiferromagnetic at the in plane anisotropy. We succeeded in interpreting these phenomena by a simple chemical bonding scheme.
(3) Mn L-MCD of Mn layer and oxidized Mn layer on Co films. Clean Mn has a ferromagnetic coupling with Co, but the exposure of O_2 only affects Mn and MnO is formed, which has, in turn, antiferromagnetic coupling with Co.
These magnetic behaviors depend on many parameters such as the kind of adsorbed molecules, adsorption site, thickness of magnetic films. Systematic study is necessary to get a deeper insight in chemical bonding of molecules and metals.
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