| Project/Area Number |
08555150
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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 | 展開研究 |
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| Research Field |
Physical properties of metals
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| Research Institution | Tohoku University |
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Principal Investigator |
OTANI Yoshichika Graduate School of Engineering, Tohoku University Associate Professor, 大学院・工学研究科, 助教授 (60245610)
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| Co-Investigator(Kenkyū-buntansha) |
KITAKAMI Osamu Research Institute of Scientific, Tohoku University Measurement Professor, 科学計測研究所, 助教授 (70250834)
SHIMADA Yutaka Research Institute of Scientific, Tohoku University Measurement Professor, 科学計測研究所, 教授 (00006157)
FUKAMICHI Kazuaki Graduate School of Engineering, Tohoku University Professor, 大学院・工学研究科, 教授 (00005969)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥10,600,000 (Direct Cost: ¥10,600,000)
Fiscal Year 1998: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥8,400,000 (Direct Cost: ¥8,400,000)
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| Keywords | Magneto-optical effect / Domain structure / Ferromagnetic dots array / Ferromagnetic wires / domain wall nucleation / Magnetoresistance |
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| Research Abstract |
The purpose of this study is to establish a novel magneto-optical diffraction technique to evaluate magnetic state in a sub-micron scale ferromagnetic substance, and to study the correlation between the magnetic state and the electronic transport properties. For this purpose, systematic studies on the 2 dimensional submicron scale dot and wire arrays were carried out by using a newly constructed magneto-optical diffractometer, a SQUID magnetometer, a high precision resistivity measurement equipment, and a magnetic force microscope. As for magneto-optics, the different orders of the diffracted light due to the array structure was found to accomodate significant magneto-optical Kerr effects. The local magnetic domain structure was successfully evaluated by taking into account the Fourier transforms of the periodical magnetic and array structures. Furthermore the diffracted light in a conical diffraction geometry was found to show Kerr effect, which provided a possible method to obtain magnetic information in the wire without an analyser. The transport experiments for the first time demonstrated that a single domain wall can be trapped in either the submicron wide wire or paired circular dots. A clear change in resistivity was found to appear in association with the domain wall nucleation and annihilation. This new phenomenon can not be explained by considering the conventional anisotropy magnetoresistance. The suppression of weak localization is suggested to be a possible mechanism. The same type of systematical studies were performed on the epitaxial Fe and Co wires, demonstrating that periodical domain walls can be stabilized in the wire. In this case, the modulation of the internal field due to the periodical domain walls are found responsible for the reduction in resistivity, that is the reduction of the surface scattering.
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