| Project/Area Number |
17310061
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanostructural science
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| Research Institution | Hiroshima University |
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Principal Investigator |
MARUYAMA Hiroshi Hiroshima University, Graduate School of Science, Professor (20181836)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Nobuo Hiroshima University, Graduate School of Science, Associate Professor (90302017)
ISHIMATSU Naoki Hiroshima University, Graduate School of Science, Assistant Professor (70343291)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥15,260,000 (Direct Cost: ¥14,600,000、Indirect Cost: ¥660,000)
Fiscal Year 2007: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2006: ¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 2005: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | FePt nano-particles / CoPt thin films / X-ray magnetic circular dichroism / Orbital magnetic moment / Ordered alloy / Angle-resolved photoemission spectroscopy / Electronic structure / 規則相FePt合金 / 磁気状態 / 規則相 / 光電子分光 / XMCD / 規則-不規則相 |
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| Research Abstract |
In this study, we aimed to clarify the correlation between magnetic anisotropy and orbital moment in ordered alloys consisting of transition metal(TM; Fe or Co) and noble metal (NM; Pt or Au). Improvement in X-ray spectroscopic experiment and systematic measurement have provided the following outcomes with a comparison between nanometer-sized materials and the bulk sample
(1) Experimental achievements:
X-ray absorption spectroscopy has been extended to the range of high pressure up to 50 GPa. We have also succeeded in angle-resolved photoemission spectroscopy for the FePt_3 ordered alloy. These techniques are advantageous to studying the nanometer-sized materials in terms of electronic structure by a comparative analysis with the bulk sample. From X-ray magnetic circular dichroism (XMCD)at the Pt L_<2,3>-edges in CoPt thin films, the orbital component of Pt 5d states was estimated, consequently it has been revealed that the orbital moment is decreased with reducing the film thickness. To
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examine the anisotropy in the orbital component, the difference in dichroic intensity between out-of plane and in-plane geometries was also recorded. These techniques are available for understanding size effect; in particular, it is valuable to link in-situ measurement with sample preparation.
(2) Scientific outcomes:
For the role of NM in the ordered alloys, hybridization between NM 5d and TM 3d orbitals is important for forming the ordered structure, in consequence the spin-orbit interaction of NM 5d states is notable for the magnetic properties. For the perpendicular magnetization thin films, however, the enhancement in magnetic anisotropy constant is not directly associated with the magnitude of orbital moment, but may be ascribed to metallographic and crystallographic structures in the thin films. From the X-ray absorption experiments of Au_4Mn ordered alloy under high pressure, some discussion for Gruneisen parameter can be developed, and the magneto-volume effect should be examined on the basis of spin-fluctuation. Less
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