| Project/Area Number |
09440143
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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 |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION |
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Principal Investigator |
FURUSAKA Michihiro (1998) HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION, Institute of Materials Structure Science Associate Professor, 物質構造科学研究所, 助教授 (60156966)
池田 宏信 (1997) 高エネルギー加速器研究機構, 物質構造科学研, 教授 (90013523)
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| Co-Investigator(Kenkyū-buntansha) |
IKEDA Hironobu HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION.Institute of Materials Structure S, 物質構造科学研究所, 教授 (90013523)
ITOH Shinichi HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION, Institute of Materials Structure, 物質構造科学研究所, 助手 (00221771)
古坂 道弘 高エネルギー加速器研究機構, 物質構造科学研, 助教授 (60156966)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 1998: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥11,000,000 (Direct Cost: ¥11,000,000)
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| Keywords | neutron scattering / pulsed neutron / fractal / percolation / self correlation function / high energy resolution / spin diffusion |
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| Research Abstract |
It was difficult to observe the diffusion of single particles on a medium by scattering techniques. Unsolved subjects among such phenomena are anomalous diffusion on a fractal lattice, the long time tail in spin diffusion on a low-dimensional lattice, and so on. The wavenumber-integration of the scattering function obtained by inelastic neutron scattering is equal to the Fourier transform of the self correlation function. This quantity was hardly obtained by a conventional neutron scattering. However, recent developments on pulsed-neutron spectroscopy enables us to observe the self correlation function in the terms of the energy spectrum, and the above listed unsolved subjects can be elucidated. The self-correlation function decays exponentially in the spin diffusion on a homogeneous medium. On a percolating network, the diffusion is anomalous and the self correlation function shows a power law. We previously observed the energy spectrum with a power law in the spin diffusion in a two-dimensional percolating magnet, Rb_2Co_<0.6>Mg_<0.4>F_4, In order to make sure that the line shape of only the near-percolating system is anomalous and that of a corresponding pure compound Rb_2CoF_4 takes the form of a Lorentzian. The observed energy spectrum was well described by a Lorentzian. We also tried to observe the long time tall in a one-dimensional magnet, CsMnBr_3. We observed energy spectrum with a power law at very small energy region. Further, we performed a high energy resolution measurement on a three-dimensional percolating magnet, RbMn_<0.39>Mg_<0.61>F_3, and firstly observed the crossover from spin wave excitations at long wavelength limit to a fracton excitations with decreasing the wavelength.
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