| Project/Area Number |
07650810
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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 | Tohoku University |
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Principal Investigator |
KONNO Toyohiko Tohoku Univ.Institute for Materials Research Research Associate, 金属材料研究所, 助手 (90260447)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Kenji Tohoku Univ.Institute for Materials Research Professor, 金属材料研究所, 教授 (10005861)
SUMIYAMA Kenji Tohoku Univ.Institute for Materials Research Associate Professor, 金属材料研究所, 助教授 (70101243)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Functional Materials / Interfacial Structure / Non-equilibrium Alloy / Ferromagnetic Materials / Transmission Electron Microscopy / 電気抵抗 |
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| Research Abstract |
We established a reproducible method to create oxygen deficient EuO thin films whose Curie temperature is about 150K.It is essential to control the reaction kinetically, not thermodynamically, in order to make such a film. We also prepared a granular film where EuO clusters are dispersed in a ferromagnetic Fe matrix. This composite film exhibits non-saturating magnetization curve at 5K,indicating that the magnetic moments of EuO and Fe align non-colinearly.
In addition, we synthesized non-equilibrium Fe-Eu alloy thin films by evaporation technique. Though the phase diagram of the system shows that Fe and Eu are immiscible even in the liquid state, our X-ray diffraction and transmission electron microscopy measurements indicated that they do form metastable alloys. The Fe-rich side of the alloy displays a ferrimagnetic character, while Eu-rich alloys exhibits a metamagnetic behavior. Longitudinal magnetoresistance of the latter has an irreversible positive component, while transverse magenetoresistance has a negative one. These transport behavior is thought to arise from breakdown of the helical order of Eu metal by the Fe impurity.
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