| Project/Area Number |
12440093
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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 | Tohoku University |
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Principal Investigator |
AOKI Haruyoshi Tohoku University, Center for Low Temperature Science, Professor, 極低温科学センター, 教授 (60302246)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Noriaki Tohoku University, Center for Low Temperature Science, Associate Professor, 極低温科学センター, 助手 (30292311)
NAKAMURA Shintaro Tohoku University, Center for Low Temperature Science, Associate Professor, 極低温科学センター, 助手 (20292310)
OCHIAI Akira Tohoku University, Center for Low Temperature Science, Associate Professor, 極低温科学センター, 助教授 (90183772)
MATSUMOTO Takehiko National Institute of Materials Science, Research Institute of Materials, Director(Researcher), 材料研究所, ディレクター(研究者) (10354185)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 2002: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2001: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2000: ¥7,400,000 (Direct Cost: ¥7,400,000)
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| Keywords | Quantum critical point / Metamagnetic Transition / Fermi surface / Strongly correlated f electron / CeRu2Si2 / 高圧 |
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| Research Abstract |
1. We have successfully developed a piston-cylinder type pressure cell which can measure the dHvA effect under pressures up to 3GPa
2. It has been demonstrated from the measurements under pressure that the metamagnetic transition in CeRu2Si2 is closely related with the quantum critical point of this compound
3. We have grown high quality single crystals of magnetic Uge_2 where superconductivity has been recently discovered under pressure. We have performed the de Haas-van Alpben (dHvA) effect measurements from the ambient pressure to the pressures beyond the quantum critical point(QCP). When the filed is applied parallel to the a-axis, the Fermi surface changes drastically across the quantum critical point(QCP) and the effective masses are enhanced around the QCP. When the field is applied parallel to the b-axis, two anomalies Bx(P) and Bm(P) are observed. Bm(P) corresponds to a metamagnetic transition and Bx(P) to the anomaly Tx. The electronic structure changes smoothly up to Bx(P) and changes drastically across Bx(P)
4. We have perfomed the dHvA measurements in ZrZn_2 and Celn_3 under pressures up to their QCP's. In ZrZn_2 we have revealed the pressure dependences of the effective mass and frequencies of the α and β oscillations which correspond to the majority and minority spin bands, respectively. The effective masses do not change significantly with pressure. The frequency difference is found to remain finite even near the QCP. The dHvA frequency and effective of CeIn3 are found to increase with pressure
5. We have revealed the pressure dependence of Fermi surface properties of PrPb_3
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