NMR and NQR Study in High-T_c superconductors : II-C Neutron Scattering, NMR and NQR and Ultrasonics : II Oxide Superconductors; Experiments II : Electronic States :

• KITAOKA,Yoshio

  Department of Material Physics, Faculty of Engineering Science, Osaka University

• ISHIDA,Kenji

  Department of Material Physics, Faculty of Engineering Science, Osaka University

• ZHENG,G.-Q.

  Department of Material Physics, Faculty of Engineering Science, Osaka University

• OHSUGI,Shigeki

  Department of Material Physics, Faculty of Engineering Science, Osaka University

• FUJIWARA,Kenji

  Department of Material Physics, Faculty of Engineering Science, Osaka University

• ASAYAMA,Kunisuke

  Department of Material Physics, Faculty of Engineering Science, Osaka University

抄録

Cu NQR and NMR, O and Tl NMR studies are extensively reported in lightly-doped La_<2-x>Sr_xCuO_4(LSCO), heavily-doped Tl_2Ba_2CuO_<6+y>(TBCO) and Zn-doped YBa_2Cu_3O_7(YBCO_7). In normal state, the nuclear spin-lattice relaxation (T_1) study has extracted that the wave number (q) dependence of the antiferromagneric (AF) spin correlation is smeared out in going from lightly-to heavily-doped system. The large AF spin correlation around the zone boundary causes the Curie-Weiss behavior of (1/T_1T) associated with that of the staggered susceptibility x_q(T) in LSCO, while the AF spin correlation becomes less distinct with lowering T_c in heavily-doped TBCO exceeding an optimum hole content and then disappears in non-superconducting TBCO, being T_1T=const. over a wide T-region. These results are indicative of an intimate interrelation between the occurrence of the superconductivity and the presence of the short-range AF spin correlation. Below T_c both the T_1 and Knight shift results have clarified that the superconducting nature are similar independent on the doping rate, being in contrast to the behavior above T_c. The NMR results in the undoped- and Zn-doped YBCO_7 and the superconducting TBCO are consistently interpreted by a simple model combining both effects of the gap zeros of line at the Fermi surface arising from d-wave pairing and of the small but finite residual density of states at the Fermi level induced by the presence of some impurity and imperfection and / or of the applied magnetic field.

収録刊行物

• JJAP series

  JJAP series 7 185-196, 1992-02-29

  Japanese Journal of Applied Physics

キーワード

• Nuclear Spin-lattice relaxation rate
• Knight shift
• La_<2-x>Sr_xCuO_4
• Tl_2Ba_2CuO_<6+y>
• Yba_2(Cu,Zn)_3O_7
• d-wave pairing
• impurity induced gapless state
• antiferromagnetic spin correlation

詳細情報

• CRID: 1540854195284296576
• NII論文ID: 110003913016
• NII書誌ID: AA11020413
• Web Site: http://dl.ndl.go.jp/info:ndljp/pid/10472402
• 本文言語コード: en
• データソース種別:
  • NDL-Digital
  • CiNii Articles