| Project/Area Number |
05452047
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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Ⅱ(磁性・金属・低温)
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
GOTO Terutaka Research Institute for Scientific Measurements, Tohoku University, 科学計測研究所, 助教授 (60134053)
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| Co-Investigator(Kenkyū-buntansha) |
KATAOKA Mituo Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (20005961)
SAKATSUME Sinichi Cryogenic Center, Tohoku University, 低温センター, 助手 (20005896)
SUZUKI Takashi Department of Physics, Tohoku University, 理学部, 教授 (30004344)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥6,800,000 (Direct Cost: ¥6,800,000)
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| Keywords | strongly correlated electron systems, electron-lattice interaction, ultrasound, quadrupole, acoustic dHvA effect, Fermi surface, superconductivity, Kondo effect / 電子-格子相互作用 / 超音波 / 四重極 / 音響ドハース効果 / フエルミ面 / 超伝導 / 近藤効果 / フェルミ面 / ヘビーフェルミオン / 希土類化合物 / 極低温 |
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| Research Abstract |
The magnetic instruction in the strongly correlated electron systems of rare earth and uranium compounds with f-electrons gives rise to unusual magnetism and superconductivity. The electron-lattice interaction has also important role for the low temperature phenomena in the f-electron system with an orbital angular momentum. In this project, we have investigated the electron-lattice interaction in the f-electron compounds by use of the ultrasonic measurements. The coupling of the quadrupole moment of the 4f-state in the crystalline field to the lattice system gives rise to a softening in the temperature dependence of the elastic constant. In the present project, we focused on the quadrupolar response of the dense Kondo system Ce_<1-x>La_xB_6 at low temperatures. The experimental evidence for the Kondo singlet in Ce_<1-x>La_xB_6 and the unusual magnetic phase diagram of an antiferro-quadruple phase have been established. Furthermore, the Kondo compound CePd_2Al_3, superconductor UPd_2Al_3 and low carrier systems CeAs, CeP has been also investigated. The acoustic dHvA effect in the f-electron compounds is very important to examine the electron-lattice interaction numerically. Kataoka and Goto have established the theory of the acoustic dHvA effect, which provides the electron-lattice interaction of the itinerant electron systems. By use of a superconducting magnet (Oxford, 14T), which is dominant cost of this project, we have measured the acoustic dHvA effect CeAs, CeP,CeBi, LaAs, HoB_<12>. More detailed investigation should be required to understand the electron-lattice interaction in the f-electron systems.
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