| Project/Area Number |
12640558
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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 |
機能・物性・材料
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| Research Institution | Kyushu University |
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Principal Investigator |
HITAKA Masako Kyushu University, Graduate School of Engineering, Research Associate, 大学院・工学研究院, 助手 (00264094)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Akinori Kyushu University, Graduate School of Engineering, Research Associate, 大学院・工学研究院, 助手 (80274512)
IDOGAKI Toshihiro Kyushu University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (40038013)
TAKEDA Kazuyoshi Kyushu University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (10029548)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | genuine organic ferromagnet / genuine organic weak-ferromagnet / Curie temperature / pressure effect / magnetic measurements / heat capacity / magnetic susceptibility / spin-Peiels transition / 有機強磁性体 / 加圧下物性測定 / 加圧下比熱 / 加圧下磁化率 / 加圧下磁化 / 加圧下構造解析 |
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| Research Abstract |
The high pressure experiment is one of the most effective way to research the fundamental mechanism of physical properties of various materials, by which we can change or control their electronic states and the overlapping of wave functions as a continuous function of pressure. We have got the following results of interest.
1. Relation between the enhanced magnetic ordering temperature and the canted magnetic moment in the genuine organic weak-ferromagnets under pressure.
2. Mechanism of the magnetic interactions which control the down-up-down-up transition temperature of the TEMPO-system radical compound in the increasing pressures.
3. Pressure effects on genuine organic ferromagnets: We have measured the magnetic susceptibility and heat capacity of the typical organic magnet NN'-dioxy-l,3,5,7-tetramethyl-2,6-diazaadamantane Tc = 1.48 K and found the negative pressure effect of the Curie temperature up to 7 kbar(Tc = 1.10 K), whose magnetic behavior quite resembles that of the prototype genuine organic ferromagnet, β-phase NPNN (Tc = 0.61K). The physics of this compound under pressures is expected to be understood in the frame work applied to the latter system.
4. Dilution effect of the genuine organic spin-Peiels system p-CyDOV: With the system (p -CYDOV)_<1-x>(p -CyDTV)_x studied by Prof. Mukai et al., we have found the concentration range where the spin-Peiels and the Neel phase coexist at low temperatures below 0.3K by the measurements of heat capacity. Following the impurity effect on the spin Peiels transition for the inorganic compounds, such as CuGeO_3, the present result is the first study with a genuine organic compound.
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