| Project/Area Number |
14204037
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | The Institute of Physical and Chemical Research |
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Principal Investigator |
KATSUMATA Koichi RIKEN, Quantum Magnetic Materials Research Team, Team Leader, 量子磁性材料研究チーム, チームリーダー (90002104)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Yoshikazu RIKEN, Coherent X-Ray Optics Laboratory, Senior Research Scientist, 石川X線干渉光学研究室, 先任研究員 (90250109)
HAGIWARA Masayuki Osaka University, Kyokugen, Professor, 極限科学研究センター, 教授 (10221491)
KINDO Koichi University of Tokyo, ISSP, Professor, 物性研究所, 教授 (20205058)
NARUMI Yasuo Osaka University, Kyokugen, Assistant Professor, 極限科学研究センター, 助手 (50360615)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥46,670,000 (Direct Cost: ¥35,900,000、Indirect Cost: ¥10,770,000)
Fiscal Year 2004: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2003: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2002: ¥39,000,000 (Direct Cost: ¥30,000,000、Indirect Cost: ¥9,000,000)
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| Keywords | Synchrotron magnetic X-ray diffraction / Field induced magnetic phase transitions / Strong magnetic fields / Highly correlated electron systems / Quantum spin systems / Spin-Peierls transition / Low carrier materials / 放射光X線磁気散乱 / 高濃度近藤物質 / 多極子秩序 / 反強磁性体 / メタ磁性 |
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| Research Abstract |
In this project, we aim at clarifying the magnetic and structural changes in quantum magnetic systems under high magnetic fields using synchrotron X-ray diffraction technique. Some of the outstanding findings obtained from this project are briefly described below.
(1)We have found that the incommensurability in the high field phase of a spin-Peierls compound, CuGeO_3 depends much on temperature near the critical field (〓12 T), while at high enough field it is independent of temperature. We have interpreted that this finding is due to a stabilization of the incommensurate state by a strong magnetic field which suppresses thermal fluctuations.
(2)At the critical field from the spin liquid to a long-range ordered phase of a spin 1/2 ladder compound Cu_2(C_5H_<12>N_2)_2Cl_4,one expects a generalized spin-Peierls transition, in which a lattice distortion is predicted to occur. We have performed X-ray diffraction study on a single crystal of this compound at the World's lowest temperature of 0.04 K and at high fields. We have found that the lattice constant along the a-axis shows a discontinuous change at the critical field.
(3)Synchrotron X-ray diffraction measurements have been performed on CeP which is a typical example of dense Kondo systems despite its small carrier concentration. In CeP two layers of Γ_8 like Ce and a layer of Γ_7 like Ce are stacked with a period which changes with an applied magnetic field. From our study performed in high fields up to 14 T we have discovered new phases with 8 and 9 periods.
(4)We are successful in developing a pulsed high field for synchrotron X-ray diffraction. We have constructed a split pair magnet capable of producing pulsed field up to 35 T without destruction and measured X-ray diffraction on some compounds.
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