| Project/Area Number |
03452034
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
IIO Katsunori Tokyo Institute of Technology, Faculty of Science, Professor, 理学部, 教授 (20016132)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Tetsuya Tokyo Institute of Technology, Faculty of Science, research associate, 理学部, 助手 (00224519)
NAGATA Kazukiyo Tokyo Institute of Technology, Faculty of Science, Professor, 理学部, 教授 (00013491)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 1993: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1992: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1991: ¥5,800,000 (Direct Cost: ¥5,800,000)
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| Keywords | Slow dynamics / Faraday rotation / Spin glass / Optical microscopic study / Magnetic phase diagram / magneto optics / competing system / Ferroelectricity / フアラデー効果 / 磁気相転移 / ランダム磁場効果 / フアラデ-効果 |
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| Research Abstract |
In condensed matter with competing interactions, inhomogeneity in specimens disturbs observation of true feature of dynamic and static properties of their multi-degenerate ordered states. To remove this difficulty, we have developed a new experimental system measuring magnetization and its long time decay on a homogeneous region extracted by means of a microscope. For the term of this research project over three years, the main task was to construct an apparetus equiped with a superconducting magnet for optical access for measuring magneto-optical effects, such as Faraday rotation and optical birefringence and to do that with an optical microscope. The final aim was to link those two systems together. Although the former system has already been operated, the latter is just settled recently.
On the other hand, a couple of research programs associated with this study bring about important results. In a mixed compound with Ising -like interaction, Fe_<1-x>MG_xCl_2, long time decay of remanent magnetization due to the random field effect and spin glass behavior could be characterized. Furthermore, as new problems inherent to competing systems, the successive phase transition accompanied with the first order transition in hexagonal layr type MnX_2(X=Br, I)were clarified with respect to magnetic structures of each phase and a mechanism of successive transition. Ferroelectricity was found in the KNICl_3 type lattice with the space group P6_3cm. The latter finding opened a new paradigm in which the physics reflecting coexistence of antiferromagnetism and ferroelectricity is attracted considerable attention. Experimental system with superconducting magnet was succeeded in measuriong the magnetic phase diagram of a triangular lattice antiferromagnet RbMnBr_3 and a layr type magnet with competing interactions NiBr_2. In this way, it takes further effort to fulfilll our project. However the prospect of the present project is rather widely opened.
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