| Project/Area Number |
10650691
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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 |
Structural/Functional materials
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
KOHMOTO Osamu Okayama University, Department of Physics, Associate Professor, 理学部, 助教授 (00234716)
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| Co-Investigator(Kenkyū-buntansha) |
FUJII Tatsuo Okayama University, Department of Applied Chemistry, Associate Professor, 工学部, 助教授 (10222259)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Nickel / Oxygen / Sputtering / Coercive Force / Heat Treatment / Magnetoresistance / Magnetic Susceptibility / 電気抵抗率 / 磁化率 / 強磁性共鳴 |
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| Research Abstract |
Four types of the magnetic films has been studied.
(1) Single-layer Ni Films : Dependencies of the saturation magnetization, coercive force remanence ratio and perpendicular magnetic anisotropy in sputtered Ni films on the film thickness (100 and 300 nm) and Ar pressure (3-50 mTorr) have been studied.
(2) Single-layer Ni-O films prepared by sputtering in Ar+OィイD22ィエD2 atmosphere : Single phase NiO films are obtained below the oxygen partial pressure (OィイD22ィエD2/(Ar+OィイD22ィエD2)) of 9%. Lattice constant (a) and axis angle (α) of the Ni-O films have been studied. With increase in OィイD22ィエD2 pressure, the two values of a and α become close to those of the bulk. Saturation magnetization, coercive force, remanence ratio and electrical resistivity (ρ) has been studied. The NiO films are not stoichiometric composition. Oxygen deficient value (γ) in NiィイD21-γィエD2O decrease rapidly with annealing temperature. With decreasing γ, the electrical resistivity increases rapidly from 6x10ィイD1-1ィエD1 to 10ィイD14ィエD1 μΩcm.
(3) Layered Ni/NiO films : Sifted MH loops are observed in bilayered films. With increase in NiO layer thickness, exchange field(HィイD2exィエD2) coercive force (HィイD2cィエD2) and magetoresistance (Δρ/ρ) increases. HィイD2exィエD2 increase with decrease in the Ni layer thickness. With increase in the NiO layer thickness, the Ni layer thickness at which the field of appearing HィイD2exィエD2 increases.
(4) Layered Ni/Cu/Ni/NiO films : Shifted and asymmetrical MH loops have been observed. The latter indicated two ferromagnetic Ni layers have been surely separated by the Cu layer. HィイD2exィエD2 and HィイD2cィエD2 tend to increase with Cu layer thickness.
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