1996 Fiscal Year Annual Research Report

新しい低次元量子スピン系無機化合物の創生とその単結晶の作成

Research Project

Project/Area Number	08640467
Research Institution	Aoyama Gakuin University
Principal Investigator	秋光純青山学院大学, 理工学部, 教授 (80013522)
Keywords	一次元磁性体 / 量子スピン系 / 梯子格子 / 超伝導 / キャリア・ド-ピング
Research Abstract	我々は、2本足梯子格子(two-leg ladder)を持つSr_<14>Cu_<24>O_<41>においてSrサイトにCaを置換することにより圧力下で超伝導が出現することを初めて明らかにした。(T_c=12K)これは、いわゆるCuO_2面を持たない系での初めての超伝導の出現である。更に、この系においてCa濃度の異なる種々の単結晶を作成し梯子格子系超伝導の物性を高温超伝導と対比させて研究した。特に、高温超伝導におけるいわゆる「異常金属相」が梯子格子系でも実現しているかどうかを輸送現象を中心に論じた。例えば梯子方向の電気抵抗率の温度変化が圧力を増加するにつれてT-linearからT^2-で変化することをみいだした。これは高温超伝導体におけるキャリア密度を変化させた時のunder-dope状態からover-dope状態への変化と対応している。しかし、この系においては梯子方向とその垂直方向ではT>T_cより上で異方性が10〜20倍も存在し準一次元性は保たれている。スピンギャップについてはCa置換とともに小さくなってゆくが、超伝導状態でもスピンギャップが存在するかどうかは技術的な制約もあり今後の課題である。

Research Products
(18 results)

All Other

All Publications (18 results)

[Publications] T.Sakaguchi,K.Kakurai,T.Yokoo,J.Akimitsu: "Neutron Scattering Study of Magnetic Excitation in the Spin S=1 One-Dimensional Heisenberg Antiferromagnet Y_2BaNiO_5" J.Phys.Soc.Jpn.65. 3025-3031 (1996)
[Publications] M.Uehara,T.Nagata,J.Akimitsu,H.Takahashi,N.Mori,K.Kinoshita: "Superconductivity in the S=1/2 Spin Ladder System Sr_<0.4>Ca_<13.6>Cu_<24>O_<41.84>" J.Phys.Soc.Jpn.65. 2764-2767 (1996)
[Publications] 銭谷勇磁、佐保田周治、秋光純、久保田伸彦、綾部統夫: "頂点臭素を含む長伝導体;(Ca,A)_2CuO_2Br_2:A=Na,K" 粉末粉体. 43. 1087-1089 (1996)
[Publications] 秋光純、上原政智: "梯子格子で超伝導" パリティ. 12. 37-40 (1996)
[Publications] 西正和、秋光純: "スピン・パイエルス系CuGeO3の研究-中性子散乱研究を中心として-" 固体物理. 31. 899-907 (1996)
[Publications] M.Sato,J.Akimitsu,H.Takahashi,N.Mori: "Effect of High Pressure on Tc of a homologous series of oxycarbonate superconductors Sr_2(Ca,Sr)_<n-1>Cu_n(C0_3)_<1-x>(BO_3)_xO_y(n=1,2)and Ba_2Ca_2Cu_3(CO_3)_<1-x>BO_3)_xO_y" Physica C. 271. 79-82 (1996)
[Publications] M.Arai,M.Fujita,M.Motokawa,J.Akimitsu,S.M.Bennington: "Quantum Spin Excitations in the Spin-Peierls CuGeO_3" Phys.Rev.Lett.77. 3649-3652 (1996)
[Publications] R.Kadono,H.Okajima,A.Yamashita,K.Ishii,T.Yokoo,J.Akimitsu,N.Kobayashi,Z.Hiroi,M.Takano,K.Nagamine: "Long-Range Magnetic Ordering in the Spin-Ladder Compound LaCuO_<2.5> Probed by Muon-Spin Relaxation" Phys.Rev.B. 54. R9628-R9630 (1996)
[Publications] N.Ogita,Y.Tsunezumi,H.Aoki,M.Udagawa,O.Fujita,A.Ogiwara,J.Akimitsu: "Raman Scattering of CuGeO_3" Physica B. 219-220. 107-109 (1996)
[Publications] Y.Tsunezuma,N.Ogita,J.Akimitsu,E.Nakamura,M.Udagawa: "Absence of the Dielectric Anormaly at Tsp of CuGeO_3" J.Phys.Soc.Jpn.65. 3403-3404 (1996)
[Publications] M.Steiner,K.Kakurai,B.Dorner,R.Pynn,J.Akimitsu: "The Change of Symmetry of the Soft-Mode Spin-Flop Transition as Observed in MnTiO_3 using Inelastic Polarized Neutron Scattering" J.Phys : Condens. Matter. 8. 5905-5914 (1996)
[Publications] T.Mizokawa,A.Fujimori,T.Arima,Y.Tokura,N.Mori,J.Akimitsu: "Photoemission and X-Ray Absorption Spectroscopy of PrNiO_3" J.Electron Spectroscopy and Related Phenomena. 78. 191-194 (1996)
[Publications] T.Ekino,H.Fujii,M.Kosugi,Y.Zenitani,J.Akimitsu: "Tunneling Spectroscopy of Superconducting Energy Gap in RNi_2B_2C(R=Y and Lu)" Phys.Rev.B. 53. 5640-5649 (1996)
[Publications] J.Akimitsu,M.Uehara,T.Nagata,S.Matsumoto,Y.Kinoshita,H.Takahashi,N.Mori: "Metal-Insurator Transition in the S=1/2 Spin-Ladder System(Sr_<0.4>Ca_<0.6>)_<14>Cu_<24-x>CoxO_<41-δ>" Physica C. 263. 475-481 (1996)
[Publications] H.Nakata,H.Okajima,T.Yokoo,A.Yamashita,J.Akimitsu: "The Phase Diagram of the New Superconductor Sr_2CuO_2(CO_3)_<1-x>(BO_3)_x" Physica C. 263. 344-348 (1996)
[Publications] I.Tamada,M.Nishi,J.Akimitsu: "Electron Paramagnetic Resonance Governed by the Dzyaloshinsky-Moriya Antisymmetric Exchange Interaction in CuGeO_3" J.Phys : Condens. Matter. 8. 2625-2640 (1996)
[Publications] 上原政智、秋光純: "梯子格子構造を有する銅酸化物へのキャリアド-ピング" 応用物理学会誌. 65. 394-400 (1996)
[Publications] M.C.Martin,G.Shirane,Y.Fujii,M.Nishi,O.Fujita,J.Akimitsu,M.Hase,K.Uchinokura: "Temperature Dependence of the Spin-Peierls Energy Gap and Anomalous Line Shapes in CuGeO_3" phys.Rev.B. 53. R14713-R14716 (1996)

1996 Fiscal Year Annual Research Report

新しい低次元量子スピン系無機化合物の創生とその単結晶の作成

Principal Investigator

秋光 純 青山学院大学, 理工学部, 教授 (80013522)

Research Products

[Publications] T.Sakaguchi,K.Kakurai,T.Yokoo,J.Akimitsu: "Neutron Scattering Study of Magnetic Excitation in the Spin S=1 One-Dimensional Heisenberg Antiferromagnet Y_2BaNiO_5" J.Phys.Soc.Jpn.65. 3025-3031 (1996)

[Publications] M.Uehara,T.Nagata,J.Akimitsu,H.Takahashi,N.Mori,K.Kinoshita: "Superconductivity in the S=1/2 Spin Ladder System Sr_<0.4>Ca_<13.6>Cu_<24>O_<41.84>" J.Phys.Soc.Jpn.65. 2764-2767 (1996)

[Publications] 銭谷勇磁、佐保田周治、秋光純、久保田伸彦、綾部統夫: "頂点臭素を含む長伝導体;(Ca,A)_2CuO_2Br_2:A=Na,K" 粉末粉体. 43. 1087-1089 (1996)

[Publications] 秋光純、上原政智: "梯子格子で超伝導" パリティ. 12. 37-40 (1996)

[Publications] 西正和、秋光純: "スピン・パイエルス系CuGeO3の研究-中性子散乱研究を中心として-" 固体物理. 31. 899-907 (1996)

[Publications] M.Sato,J.Akimitsu,H.Takahashi,N.Mori: "Effect of High Pressure on Tc of a homologous series of oxycarbonate superconductors Sr_2(Ca,Sr)_<n-1>Cu_n(C0_3)_<1-x>(BO_3)_xO_y(n=1,2)and Ba_2Ca_2Cu_3(CO_3)_<1-x>BO_3)_xO_y" Physica C. 271. 79-82 (1996)

[Publications] M.Arai,M.Fujita,M.Motokawa,J.Akimitsu,S.M.Bennington: "Quantum Spin Excitations in the Spin-Peierls CuGeO_3" Phys.Rev.Lett.77. 3649-3652 (1996)

[Publications] R.Kadono,H.Okajima,A.Yamashita,K.Ishii,T.Yokoo,J.Akimitsu,N.Kobayashi,Z.Hiroi,M.Takano,K.Nagamine: "Long-Range Magnetic Ordering in the Spin-Ladder Compound LaCuO_<2.5> Probed by Muon-Spin Relaxation" Phys.Rev.B. 54. R9628-R9630 (1996)

[Publications] N.Ogita,Y.Tsunezumi,H.Aoki,M.Udagawa,O.Fujita,A.Ogiwara,J.Akimitsu: "Raman Scattering of CuGeO_3" Physica B. 219-220. 107-109 (1996)

[Publications] Y.Tsunezuma,N.Ogita,J.Akimitsu,E.Nakamura,M.Udagawa: "Absence of the Dielectric Anormaly at Tsp of CuGeO_3" J.Phys.Soc.Jpn.65. 3403-3404 (1996)

[Publications] M.Steiner,K.Kakurai,B.Dorner,R.Pynn,J.Akimitsu: "The Change of Symmetry of the Soft-Mode Spin-Flop Transition as Observed in MnTiO_3 using Inelastic Polarized Neutron Scattering" J.Phys : Condens. Matter. 8. 5905-5914 (1996)

[Publications] T.Mizokawa,A.Fujimori,T.Arima,Y.Tokura,N.Mori,J.Akimitsu: "Photoemission and X-Ray Absorption Spectroscopy of PrNiO_3" J.Electron Spectroscopy and Related Phenomena. 78. 191-194 (1996)

[Publications] T.Ekino,H.Fujii,M.Kosugi,Y.Zenitani,J.Akimitsu: "Tunneling Spectroscopy of Superconducting Energy Gap in RNi_2B_2C(R=Y and Lu)" Phys.Rev.B. 53. 5640-5649 (1996)

[Publications] J.Akimitsu,M.Uehara,T.Nagata,S.Matsumoto,Y.Kinoshita,H.Takahashi,N.Mori: "Metal-Insurator Transition in the S=1/2 Spin-Ladder System(Sr_<0.4>Ca_<0.6>)_<14>Cu_<24-x>CoxO_<41-δ>" Physica C. 263. 475-481 (1996)

[Publications] H.Nakata,H.Okajima,T.Yokoo,A.Yamashita,J.Akimitsu: "The Phase Diagram of the New Superconductor Sr_2CuO_2(CO_3)_<1-x>(BO_3)_x" Physica C. 263. 344-348 (1996)

[Publications] I.Tamada,M.Nishi,J.Akimitsu: "Electron Paramagnetic Resonance Governed by the Dzyaloshinsky-Moriya Antisymmetric Exchange Interaction in CuGeO_3" J.Phys : Condens. Matter. 8. 2625-2640 (1996)

[Publications] 上原政智、秋光純: "梯子格子構造を有する銅酸化物へのキャリアド-ピング" 応用物理学会誌. 65. 394-400 (1996)

[Publications] M.C.Martin,G.Shirane,Y.Fujii,M.Nishi,O.Fujita,J.Akimitsu,M.Hase,K.Uchinokura: "Temperature Dependence of the Spin-Peierls Energy Gap and Anomalous Line Shapes in CuGeO_3" phys.Rev.B. 53. R14713-R14716 (1996)

秋光純青山学院大学, 理工学部, 教授 (80013522)