2002 年度実績報告書

磁場が誘起するマグノンのボース・アインシュタイン凝縮と局在

研究課題

研究課題/領域番号	13130202
研究機関	東京工業大学
研究代表者	田中秀数東京工業大学, 極低温物性研究センター, 教授 (80188325)
研究分担者	細越裕子大阪府立大学, 総合科学部, 助教授 (50290903) 小野俊雄東京工業大学, 大学院・理工学研究科, 助手 (40332639) 押川正毅東京工業大学, 大学院・理工学研究科, 助教授 (50262043)
キーワード	スピンギャップ / マグノン / ボース・アインシュタイン凝縮 / ESR / 磁場誘起相転移 / 磁化プラトー / TlCuCl_3 / F_2PNNNO
研究概要	科研費特定領域研究の支援の下で,本年度は以下の研究実績を上げた. 1.スピンギャップ系TlCuCl_3の磁場誘起相転移はマグノンのボース・アインシュタイン凝縮(以下ボース凝縮と略す)として理解できるが,液体He等とのアナロジーを通じて熱伝導に異常が現れる可能性を指摘,実験的研究を示唆した.また東北大学グループとの共同研究により,磁場誘起相転移に伴ってマグノンの熱伝導が異常に増大することを観測した.これはマグノンのボース凝縮と一致する結果である. 2.ドイツのブラウンシュヴァイク工科大学グループとの共同研究でTlCuCl_3の磁場誘起相転移を超音波吸収実験で調べ,様々な温度での吸収係数の磁場依存性がマグノンのボース凝縮の観点からよく説明できることを示した.相転移温度の磁場依存性がべき乗則で表されるが,べきの実験値が2に近く,通常のボース凝縮理論が与える3/2からずれる結果が得られている.今回,磁気励起の分散が放物線からずれる効果を取り込むと,この実験結果を説明できることを示した. 3.TlCuCl_3のギャップが圧力で閉じることを見出し,磁気測定と中性子散乱でTlCuCl_3の圧力誘起相転移を詳細に調べた.また非磁性イオンMg^<2+>で磁性イオンCu^<2+>を置換した系TlCu_<1-x>Mg_xCl_3で不純物誘起反強磁性秩序を確認し,スピンギャップが秩序変数に比例して増大することを発見した. 4.有機物磁性体F_2PNNNOを合成し,これがS=1の歪んだ蜂の巣格子として記述できることを示し,強磁場磁化測定から飽和磁化の1/2に磁化プラトーを発見した.またNMRによって磁場誘起相転移を観測し,その詳細を調べている.更に有機物一次元交互反強磁性体F_5PNNについても比熱測定から磁場中相転移を発見した. 5.S=1/2の歪んだ三角格子反強磁性体Cs_2CuBr_4を開拓し,理論的に予測されていた量子揺らぎによる1/3磁化プラトーを初めて発見した.また磁化プラトー状態でのスピン構造を磁場中中性子散乱で決定した.

研究成果

(27件)

すべてその他

すべて文献書誌 (27件)

[文献書誌] A.Oosawa: "Magnetic Excitations in the Spin Gap System TlCuCl_3"Phys.Rev. B. 65. 094426-1-094426-7 (2002)
[文献書誌] S.Itoh: "Classical Properties in Spin Dynamics in the S=2 One-Dimensional Heisenberg Antiferromagnet, CsCrCl_3"J.Phys.Soc.Jpn.. 71. 1148-1153 (2002)
[文献書誌] H.Takeuchi: "EPR Study of Several Cr^<3+> Centers in K_2MgCl_4 Single Crystal"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 213-218 (2002)
[文献書誌] T.Ono: "ESR Measurements on Triangular Antiferromagnets CsCu_<1-x>Co_xCl_3"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 775-778 (2002)
[文献書誌] A.Oosawa: "Random Bond Effect in the Quantum Spin System (Tl^<1-x>K_x)CuCl_3"Phys.Rev. B. 65. 184437-1-184437-7 (2002)
[文献書誌] H.Tanaka: "Magnetic Phase Transition and Magnetization Plateau in Cs_2CuBr_4"Prog.Theor.Phys.Suppl.. No.145. 101-106 (2002)
[文献書誌] O.Vyaselev: "Lattice Distortion and First Order Transition in TlCuCl_3"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 55-61 (2002)
[文献書誌] H.Tanaka: "Field-Induced Quantum Magnetism in TlCuCl_3"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 47-54 (2002)
[文献書誌] H.Nojiri: "ESR Study on Spin-Gap Compounds with Magnetization Plateaux"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 19-26 (2002)
[文献書誌] A.Oosawa: "Impurity-Induced Antiferromagnetic Ordering in the Spin Gap System TlCuCl_3"Phys.Rev. B. 66. 020405-1-020405-4 (2002)
[文献書誌] M.Uchida: "High-Field Magnetization Process in an S=1 Quantum Spin System Ba_3Mn_2O_8"Phys.Rev. B. 66. 054429-1-054429-6 (2002)
[文献書誌] A.Oosawa: "Field-Induced Magnetic Ordering in the Quantum Spin System KCuCl_3"Phys.Rev. B. 66. 104405-1-104405-7 (2002)
[文献書誌] A.Oosawa: "Magnetic Excitations and Exchange Interactions in the Spin Gap System TlCuCl_3"Appl.Phys. A Suppl.. 74. 846-849 (2002)
[文献書誌] T.Ono: "Spin Structure of CsCu_<1-x>Co_xCl_3 in the Magnetic Field"Appl.Phys. A Suppl.. 74. 728-730 (2002)
[文献書誌] M.Fujisawa: "Crystal Structure and Magnetic Properties of the Quasi-One-Dimensional Quantum Spin System Cu_2Cl_4・H_8C_4SO_2"J.Phys.Soc.Jpn.. 72. 694-697 (2003)
[文献書誌] M.Oshikawa: "Electron Spin Resonance in S=1/2 Antiferromagnetic Chains"Phys.Rev. B. 65. 134410-1-134410-28 (2002)
[文献書誌] K.Mukai: "Anomalous magnetic behavior in three kinds of 3-(aryl-substituted)-1,5-diphenyl-verdazyl radical crystals (p-FPDV, p-PyDV and m-PyDV) induced by frustrated spin interaction"J.Phys.Chem. B. 106. 8632-8638 (2002)
[文献書誌] H.Ohta: "Low Dimensionality Observed by ESR Measurements in S=1 Spin Ladder Substance BIP-TENO (3,3',5,5'-tetrakis(N-tert-butyl-aminoxyl)biphenyl)"J.Phys.Soc.Jpn.. 71. 2640-2643 (2002)
[文献書誌] K.Hino: "Photochemical generation of high spin clusters in solution : (Cyclopentadienyl-vanadium)(m)O-n"J.Phys.Chem.B. 106. 1290-1293 (2002)
[文献書誌] K.Suzuki: "Pressure-induced metamagnetic behavior in a quasi-one-dimensional molecule-based ferrimagnet"Chem.Lett.. No.3. 316-317 (2002)
[文献書誌] K.Kirita: "X-band ESR Measurements of Spin Ladder System BIP-TENO"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 69-72 (2002)
[文献書誌] K.Suzuki: "Pressure Effects on Molecular Magnets of Mn Complexes with Bisaminoxylbenzene Derivatives"Mol.Cryst.Liq.Cryst.. 379. 247-252 (2002)
[文献書誌] K.Katoh: "Magnetic properties of organic two-leg spin ladder systems with S=1/2 and S=1"J.Phys.Chem.Solids. 63. 1277-1280 (2002)
[文献書誌] N.Azuma: "Synthesis and magnetic property of the salts of positively charged verdazyl radicals and TCNQF_4 anion radical"Mol.Cryst.Liq.Cryst.. 376. 341-346 (2002)
[文献書誌] M.Inokuchi: "Magnetic properties of Cs and N(CH_3)_4 salts of TCNQ"Mol.Cryst.Liq.Cryst.. 376. 507-512 (2002)
[文献書誌] S.Aonuma: "Structure and property of M(dmit)_2 salt with trimethylammonio-TEMPO and related magnetic organic cations"Mol.Cryst.Liq.Cryst.. 130. 263-269 (2002)
[文献書誌] K.Nagayoshi: "Design of Novel Inorganic-Organic Hybrid Materials Based on Iron-Chloranilate Mononuclear Complexes : Characteristics of Hydrogen-Bond-Supported Layers toward the Intercalation of Guests"J.Am.Chem.Soc.. 125. 221-232 (2003)

2002 年度 実績報告書

磁場が誘起するマグノンのボース・アインシュタイン凝縮と局在

研究代表者

田中 秀数 東京工業大学, 極低温物性研究センター, 教授 (80188325)

研究成果

[文献書誌] A.Oosawa: "Magnetic Excitations in the Spin Gap System TlCuCl_3"Phys.Rev. B. 65. 094426-1-094426-7 (2002)

[文献書誌] S.Itoh: "Classical Properties in Spin Dynamics in the S=2 One-Dimensional Heisenberg Antiferromagnet, CsCrCl_3"J.Phys.Soc.Jpn.. 71. 1148-1153 (2002)

[文献書誌] H.Takeuchi: "EPR Study of Several Cr^<3+> Centers in K_2MgCl_4 Single Crystal"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 213-218 (2002)

[文献書誌] T.Ono: "ESR Measurements on Triangular Antiferromagnets CsCu_<1-x>Co_xCl_3"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 775-778 (2002)

[文献書誌] A.Oosawa: "Random Bond Effect in the Quantum Spin System (Tl^<1-x>K_x)CuCl_3"Phys.Rev. B. 65. 184437-1-184437-7 (2002)

[文献書誌] H.Tanaka: "Magnetic Phase Transition and Magnetization Plateau in Cs_2CuBr_4"Prog.Theor.Phys.Suppl.. No.145. 101-106 (2002)

[文献書誌] O.Vyaselev: "Lattice Distortion and First Order Transition in TlCuCl_3"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 55-61 (2002)

[文献書誌] H.Tanaka: "Field-Induced Quantum Magnetism in TlCuCl_3"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 47-54 (2002)

[文献書誌] H.Nojiri: "ESR Study on Spin-Gap Compounds with Magnetization Plateaux"Proc. French-Japanese Symposium on Quantum Properties of Low-Dimensional Antiferromagnets, Fukuoka, 2001;九州大学出版会. 19-26 (2002)

[文献書誌] A.Oosawa: "Impurity-Induced Antiferromagnetic Ordering in the Spin Gap System TlCuCl_3"Phys.Rev. B. 66. 020405-1-020405-4 (2002)

[文献書誌] M.Uchida: "High-Field Magnetization Process in an S=1 Quantum Spin System Ba_3Mn_2O_8"Phys.Rev. B. 66. 054429-1-054429-6 (2002)

[文献書誌] A.Oosawa: "Field-Induced Magnetic Ordering in the Quantum Spin System KCuCl_3"Phys.Rev. B. 66. 104405-1-104405-7 (2002)

[文献書誌] A.Oosawa: "Magnetic Excitations and Exchange Interactions in the Spin Gap System TlCuCl_3"Appl.Phys. A Suppl.. 74. 846-849 (2002)

[文献書誌] T.Ono: "Spin Structure of CsCu_<1-x>Co_xCl_3 in the Magnetic Field"Appl.Phys. A Suppl.. 74. 728-730 (2002)

[文献書誌] M.Fujisawa: "Crystal Structure and Magnetic Properties of the Quasi-One-Dimensional Quantum Spin System Cu_2Cl_4・H_8C_4SO_2"J.Phys.Soc.Jpn.. 72. 694-697 (2003)

[文献書誌] M.Oshikawa: "Electron Spin Resonance in S=1/2 Antiferromagnetic Chains"Phys.Rev. B. 65. 134410-1-134410-28 (2002)

[文献書誌] K.Mukai: "Anomalous magnetic behavior in three kinds of 3-(aryl-substituted)-1,5-diphenyl-verdazyl radical crystals (p-FPDV, p-PyDV and m-PyDV) induced by frustrated spin interaction"J.Phys.Chem. B. 106. 8632-8638 (2002)

[文献書誌] H.Ohta: "Low Dimensionality Observed by ESR Measurements in S=1 Spin Ladder Substance BIP-TENO (3,3',5,5'-tetrakis(N-tert-butyl-aminoxyl)biphenyl)"J.Phys.Soc.Jpn.. 71. 2640-2643 (2002)

[文献書誌] K.Hino: "Photochemical generation of high spin clusters in solution : (Cyclopentadienyl-vanadium)(m)O-n"J.Phys.Chem.B. 106. 1290-1293 (2002)

[文献書誌] K.Suzuki: "Pressure-induced metamagnetic behavior in a quasi-one-dimensional molecule-based ferrimagnet"Chem.Lett.. No.3. 316-317 (2002)

[文献書誌] K.Kirita: "X-band ESR Measurements of Spin Ladder System BIP-TENO"EPR IN THE 21ST CENTURY : BASICS, AND APPLICATION TO MATERIAL, LIFE AND EARTH SCIENCES ; Elsevier. 69-72 (2002)

[文献書誌] K.Suzuki: "Pressure Effects on Molecular Magnets of Mn Complexes with Bisaminoxylbenzene Derivatives"Mol.Cryst.Liq.Cryst.. 379. 247-252 (2002)

[文献書誌] K.Katoh: "Magnetic properties of organic two-leg spin ladder systems with S=1/2 and S=1"J.Phys.Chem.Solids. 63. 1277-1280 (2002)

[文献書誌] N.Azuma: "Synthesis and magnetic property of the salts of positively charged verdazyl radicals and TCNQF_4 anion radical"Mol.Cryst.Liq.Cryst.. 376. 341-346 (2002)

[文献書誌] M.Inokuchi: "Magnetic properties of Cs and N(CH_3)_4 salts of TCNQ"Mol.Cryst.Liq.Cryst.. 376. 507-512 (2002)

[文献書誌] S.Aonuma: "Structure and property of M(dmit)_2 salt with trimethylammonio-TEMPO and related magnetic organic cations"Mol.Cryst.Liq.Cryst.. 130. 263-269 (2002)

[文献書誌] K.Nagayoshi: "Design of Novel Inorganic-Organic Hybrid Materials Based on Iron-Chloranilate Mononuclear Complexes : Characteristics of Hydrogen-Bond-Supported Layers toward the Intercalation of Guests"J.Am.Chem.Soc.. 125. 221-232 (2003)

2002 年度実績報告書

田中秀数東京工業大学, 極低温物性研究センター, 教授 (80188325)