1994 Fiscal Year Annual Research Report

分子性物質の電子相関と電子構造

Research Project

Project/Area Number	06243102
Research Institution	The University of Tokyo
Principal Investigator	鹿児島誠一東京大学, 教養学部, 教授 (30114432)
Co-Investigator(Kenkyū-buntansha)	薬師久弥東京大学, 分子科学研究所, 教授 (20011695) 豊田直樹大阪府立大学, 附属研究所, 教授 (50124607) 大嶋孝吉岡山大学, 理学部, 教授 (10114414) 石黒武彦京都大学, 理学部, 教授 (50202982) 池畑誠一郎東京大学, 大学院・理学系研究科, 助教授 (30107685)
Keywords	分子性導体 / 電子相関 / BEDT-TTF / フェルミ面 / 金属-非金属転移 / 再入転移 / 超伝導 / DCNQI
Research Abstract	本研究の目的は分子性導体の電子状態の特徴を探り,電子相関の役割を実験的に解明することである。基本物性の解明と新物性の探索を車の両輪とし,特徴ある測定法と新しい試みの開拓をこれと並行して進める。基本物性の解明では,BEDT-TTF系2次元導体の電子構造を,温度,圧力,磁場をパラメターとして詳細に調べ,フェルミ面のトポロジーと電子状態の関係を吟味した。また,この系では金属-非金属転移とともに,反強磁性・寄生強磁性などが現れることを磁気測定によって明らかにし,金属電子状態の電子相関について考察を進めた。さらに,この系の超伝導の対称性を探った。DCNQI-Cu系物質では再入転移にかかわる金属相,絶縁相それぞれの基本的性質を解明したが,再入転移の機構については未解決である。新物性の探索では,DCNQI系物質の核磁気共鳴によって1次元的バンドと3次元的バンドの電子状態を区別して調べ,電子状態を新たな角度から探ることを始めた。また,BEDT-TTF系物質で,強磁場下での磁気貫通と量子振動の関係という新たな現象を吟味した。特徴ある測定法として,光電子分光法ではDCNQI-Cu系物質のその場観察を試み,従来の結果よりやや2価イオンの割合が少ないという結果を得た。ラマン錯乱では,DCNQI-Cu系物質でのCuイオンの秩序化に伴うピークなどを見出した。新しい試みとして,伝導バンド充填率の制御をめざして,BEDT-TTF分子とTCNQ系分子との錯体の電子状態を探り,反強磁性状態や金属状態を発見した。また,コバルトフタロシアニンの電子状態の究明や,ペンタセンのn型ド-ピングによる新たな分子性導体の開発を試みている。

Research Products
(16 results)

All Other

All Publications (16 results)

[Publications] S.Kagoshima: "Magnetic-field effects on the reentrance transition of alloy of pristine and fully deuterated (DMeDCNQI)_2Cu" Synthetic Metals. (印刷中). (1995)
[Publications] S.Kagoshima: "Heat capacity and magnetoresistance of the alloy of pristine and fully deuterated(DMeDCNQI)2Cu-Is the heavy electron model applicable?" Physica B. 201. 493-496 (1994)
[Publications] T.Ishiguro: "Interplay of superconductivity with magnetism in two-dimensional organic salts" J.Superconductivity. 7-3. 657-661 (1994)
[Publications] K.Oshima: "Superconductivity and Field Induced States in DMET-TSeF Family" Synthetic Metals. (印刷中). (1995)
[Publications] T.Osada: "Density-Wave v.s.Magnetic Breakdown: Mechanism of High-Field Phase Transition in α-(BEDT-TTF)_2XHg(SCN)_4" Synthetic Metals. (印刷中). (1995)
[Publications] T.Mishima: "Extremely high mobility carriers in organic conductor α-(BEDT-TTF)_2I_3 under high pressure" Materials Science and Engineering. B25. L1-L5 (1994)
[Publications] K.Kanoda: "^<13>C-NMR study on α-(BEDT-TTF)_2MHg(SCN)_4" Synthetic Metals. (印刷中). (1995)
[Publications] A.Kawamoto: "Systematic study of DCNQI-Cu salts by NMR at selective nuclear sites" Synthetic Metals. (印刷中). (1995)
[Publications] T.Sekine: "Low-frequency Raman spectra in κ-(BEDT-TTF)_2Cu(NCS)_2 and κ-(BEDT-TTF)_2Cu[N(CN)_2]Br" Synthetic Metals. (印刷中). (1995)
[Publications] A.Tanaka: "Synchrotron-radiation photoemission study of in-situ synthesized DCNQI(N,N´-dicyanoquinonediimine)-Cu salts" Solid State Commun.93. 1-5 (1995)
[Publications] T.Takahashi: "Symmetry of the Order Parameter in Organic Superconductors:(MDT-TTF)_2AuI_2 vs.(TMTSF)_2C10_4" Physica C. 235-240. 2461-2462 (1994)
[Publications] T.Nakamura: "ESR Properties of κ-Type Organic Superconductors Based on BEDT-TTF" J.Phys.Soc.Jpn.63. 4110-4125 (1994)
[Publications] T.Sasaki: "Anisotropic galvanomagnetic effect in the quasi-two-dimensional organic conductor α-(BEDT-TTF)2KHg(SCN)4,where BEDT-TTF is bis(ethylenedithio) tetrathiafulvalene" Phys.Rev.B. 49. 10120-10130 (1994)
[Publications] I.I.Khairullin: "X- and Q-band ESR Study of New Poly-CuPc Compounds Synthesized under High Pressure: The Possibility of Two-Dimensional Sheet Polymers" Synthetic Metals. 64. 217-225 (1994)
[Publications] H.Yamakado: "Structure and solid state properties of stable ring-oxidized conductor CoPc(AsF_6)_<0.5>:lnteraction between ring π-electrons and cobalt d-electrons" Synthetic Metals. 62. 169-178 (1994)
[Publications] T.Sugawara: "An Organic Ferromagnet:α-Phase Crystal of 2-(2',5'-Dyhydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1 Himidazolyl-I-oxy-3-oxide" J.Chem.Soc.,Chem.Commun.1723-1724 (1994)

1994 Fiscal Year Annual Research Report

分子性物質の電子相関と電子構造

Principal Investigator

鹿児島 誠一 東京大学, 教養学部, 教授 (30114432)

Research Products

[Publications] S.Kagoshima: "Magnetic-field effects on the reentrance transition of alloy of pristine and fully deuterated (DMeDCNQI)_2Cu" Synthetic Metals. (印刷中). (1995)

[Publications] S.Kagoshima: "Heat capacity and magnetoresistance of the alloy of pristine and fully deuterated(DMeDCNQI)2Cu-Is the heavy electron model applicable?" Physica B. 201. 493-496 (1994)

[Publications] T.Ishiguro: "Interplay of superconductivity with magnetism in two-dimensional organic salts" J.Superconductivity. 7-3. 657-661 (1994)

[Publications] K.Oshima: "Superconductivity and Field Induced States in DMET-TSeF Family" Synthetic Metals. (印刷中). (1995)

[Publications] T.Osada: "Density-Wave v.s.Magnetic Breakdown: Mechanism of High-Field Phase Transition in α-(BEDT-TTF)_2XHg(SCN)_4" Synthetic Metals. (印刷中). (1995)

[Publications] T.Mishima: "Extremely high mobility carriers in organic conductor α-(BEDT-TTF)_2I_3 under high pressure" Materials Science and Engineering. B25. L1-L5 (1994)

[Publications] K.Kanoda: "^<13>C-NMR study on α-(BEDT-TTF)_2MHg(SCN)_4" Synthetic Metals. (印刷中). (1995)

[Publications] A.Kawamoto: "Systematic study of DCNQI-Cu salts by NMR at selective nuclear sites" Synthetic Metals. (印刷中). (1995)

[Publications] T.Sekine: "Low-frequency Raman spectra in κ-(BEDT-TTF)_2Cu(NCS)_2 and κ-(BEDT-TTF)_2Cu[N(CN)_2]Br" Synthetic Metals. (印刷中). (1995)

[Publications] A.Tanaka: "Synchrotron-radiation photoemission study of in-situ synthesized DCNQI(N,N´-dicyanoquinonediimine)-Cu salts" Solid State Commun.93. 1-5 (1995)

[Publications] T.Takahashi: "Symmetry of the Order Parameter in Organic Superconductors:(MDT-TTF)_2AuI_2 vs.(TMTSF)_2C10_4" Physica C. 235-240. 2461-2462 (1994)

[Publications] T.Nakamura: "ESR Properties of κ-Type Organic Superconductors Based on BEDT-TTF" J.Phys.Soc.Jpn.63. 4110-4125 (1994)

[Publications] T.Sasaki: "Anisotropic galvanomagnetic effect in the quasi-two-dimensional organic conductor α-(BEDT-TTF)2KHg(SCN)4,where BEDT-TTF is bis(ethylenedithio) tetrathiafulvalene" Phys.Rev.B. 49. 10120-10130 (1994)

[Publications] I.I.Khairullin: "X- and Q-band ESR Study of New Poly-CuPc Compounds Synthesized under High Pressure: The Possibility of Two-Dimensional Sheet Polymers" Synthetic Metals. 64. 217-225 (1994)

[Publications] H.Yamakado: "Structure and solid state properties of stable ring-oxidized conductor CoPc(AsF_6)_<0.5>:lnteraction between ring π-electrons and cobalt d-electrons" Synthetic Metals. 62. 169-178 (1994)

[Publications] T.Sugawara: "An Organic Ferromagnet:α-Phase Crystal of 2-(2',5'-Dyhydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1 Himidazolyl-I-oxy-3-oxide" J.Chem.Soc.,Chem.Commun.1723-1724 (1994)

鹿児島誠一東京大学, 教養学部, 教授 (30114432)