| Project/Area Number |
61460031
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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 | University of Osaka Prefecture |
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Principal Investigator |
OKUDA Kiichi College of Engineering, University of Osaka Prefecture, 工学部, 助教授 (50028205)
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| Co-Investigator(Kenkyū-buntansha) |
NOGUCHI Satoru College of Engineering, University of Osaka Prefecture, 工学部, 助手 (70180718)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1987: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1986: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Heavy fermion / Electron spin xesonance / Uranium compounds / セリウム化合物 / ヘビーフェルミオン系化合物 / ESR |
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| Research Abstract |
Four work were done in the present project. 1) To investigate the spin dynamics of heavy fermion systaems in the coherent kondo state which is usually realized below 1 K, we developed the ESR cryostat which is available at low temperatures down to 200 mk by using a combined ^33He-demagnetization method. Sensitivity of the constructer ESR cryostat was about 10^<13>13 spins/Oe near 200 mk.
2) Temperature dependence of ESR line width of Gd^<3+>3 ions doped in the heavy fermion compounds CeSn_33 and CeCu_66 was measured. The line width was increased linearly with increasing the temperaturc. The increasing rate of the line width was almost same as that in the noble metals on the contrary to the expectation of high increasing rate for the heavy fermion compounds with high electronic specific heat <gamma>. This fact suggests that the average real band polarization near the Fermi surface is not so large. It is important result in the present work and gives a key point to understand the mechanism of high <gamma>-state.
3) Uranium compounds with high <gamma> value, U_66 Ni and USn_33, were synthesized by arc-melting and the magnetic properties were investigated by magnetic susceptibility measurements. The susceptibility of U_66 Ni was almost independent on the temperature and the value is estimated to be 2.5 x 10^1323 emu/mole, suggesting the band paramagnetism of U_66 Ni. On the other hand, the susceptibility of USn_33 follows the Curie-Weiss law above 20 K. Below 20 K, however, the susceptibility becomes constant.
4) Supercondcuting transition eemperature Tc and upper critical field Hc_22 (T) in the Ce-doped system Ce_xx La_<1-x>1-x Mo_66 S_88 were investigated by magnetoresistance measurements. The results were successfully explained by the Kondo effect in the superconductor.
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