1992 Fiscal Year Final Research Report Summary
Roles of Transition Metal d-Electrons in Electronic Properties of Organic Low-Dimensional Conductors
Project/Area Number |
02452035
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
固体物性
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Research Institution | University of Tokyo |
Principal Investigator |
KAGOSHIMA Seiichi University of Tokyo, Department of Pure and Applied Sciences, Professor, 教養学部, 教授 (30114432)
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Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Hayao Toho University, Department of Chemistry, Professor, 理学部, 教授 (60057635)
OSADA Toshihito University of Tokyo, Research Center for Advanced Science and Technology, Lectur, 先端科学技術研究センター, 講師 (00192526)
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Project Period (FY) |
1990 – 1992
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Keywords | Organic Conductor / Low Dimensional Conductor / Transition Metal Elements / Metal-Insulator Transition / Reentrance / Magnetoresistance |
Research Abstract |
The purpose of the present study is to clarify roles of transition metal delectrons in electronic properties of organic low-dimensional conductors having transition metal ions. The experimental research was focused to investigation of properties of conduction electrons predominantly in DCNQI-Cu salts. In dmit salts characterization of electronic properties was made. Special effort was made in studying electronic properties near the reentrance transition of (DMeDCNQI)_2Cu. The followings are important results obtained in the present work: (1) The average valence of the copper ion in DCNQI-Cu slats was verified experimentally to be +4/3. (3) The magnetic structure of the anti-ferromagnetic state below about 8 K was made clear in the insulating state of DCNQI-Cu salts having the three-fold structure along the c-axis. (4) The reentrance transition in DMeDCNQI-Cu salt is accompanied with anomalies in the magnetic susceptibility, the three-fold structure, and the distortion around the copper ion. (5) Near the reentrance transition of DCNQI-Cu salts properties characteristic of the insulating state are present already in the metallic state. Furthermore magnetic fields as low as 10 T stabilize the insulating state. (6) In dmit salts both electron- and hole-like superconductivities were found. In addition both one- and two-dimensional properties were found depending on species of the metal ion. We clarified that the electronic state of DCNQI-Cu salts is described in terms of the Peierls instability in the one-dimensional band formed by pi electrons of DCNQI, the Mott transition of the band formed predominantly by the d-electrons of copper ions, the Jahn-Teller effect of copper ions, and electronphonon interactions in the "soft" lattice. It is remained unsolved to reveal microscopic mechanisms of the reentrance transition.
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Research Products
(38 results)
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[Publications] M.Tamura,R.Masuda,T.Naito,H.Tajima,H,Kuroda,A.Kobayashi,K.Yakushi,R.Kato,H.Kobayashi,M.Tokumoto,N.Kinoshita,and H.Anzai: "Reflectance Spectra of Some Two-Dimensional Organic Metals Based on BEDT-TTF and [Ni(dmit)_2" Synthetic Metals. 41-43. 2499-2502 (1991)
Description
「研究成果報告書概要(和文)」より
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[Publications] H.Kobayashi,A.Miyamoto,R.Kato,F.Sakai,A.Kobayashi,Y.Yamakita,Y.Furukawa,M.Tasumi,and T.Watanabe: "Mixed Valency of Cu,Electron-Mass Enhancement,and Three-Dimensional Arrangement of Magnetic Sites in the Organic Conductors (R_1,R_2-N,N'-Dicyanoquinonediimine)_2Cu (where R_1,R_2=CH_3,CH_3O,Cl,Br)" Phys.Rev.b. 47. (1993)
Description
「研究成果報告書概要(和文)」より
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[Publications] S.Kagoshima,A,Miyazaki,T.Osada,Y.saito,N.Wada,H.Yano,T.Takahashi,K.Kanoda,H.Kobayashi,A.Kobayashi,and R.Kato: "Charge and Spin States of DCNQI-Cu Salts" Synthetic Metals. 54. (1993)
Description
「研究成果報告書概要(和文)」より
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[Publications] M.Tamura, R.Masuda, T.Naito, H.Tajima, H.Kuroda, A.Kobayashi, K.Yakushi, R.Kato, H.Kobayashi, M.Tokumoto, N.Kinoshita, and H.Anzai: "Reflectance Spectra of Some Two-Dimensional Organic Metals Based on BEDT-TTF and [Ni(dmit)_2]" Synthetic Metals. Vol.41-43. 2499-2502 (1991)
Description
「研究成果報告書概要(欧文)」より
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[Publications] H.Kobayashi, A.Miyamoto, R.Kato, F.Sakai, A.Kobayashi, Y.Yamakita, Y.Furukawa, M.Tasumi, and T.Watanabe: "Mixed Valency of Cu, Electron-Mass Enhancement, and Three-Dimensional Arrangement of Magnetic Sites in the Organic Conductors (R_1,R_2-N,N'-Dicyanoquinonediimine)_2Cu (where R_1, R_2 = CH_3, CH_3O, Cl, Br)" Phys. Rev. B. Vol.47. (1993)
Description
「研究成果報告書概要(欧文)」より
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[Publications] S.Kagoshima, A.Miyazaki, T.Osada, Y.Saito, N.Wada, H.Yano, T.Takahashi, K.Kanoda, H.Kobayashi, A.Kobayashi, and R.Kato: "Charge and Spin States of DCNQI-Cu Salts" Synthetic Metals. Vol.54. (1993)
Description
「研究成果報告書概要(欧文)」より