CU NMR-STUDY IN SINGLE-CRYSTAL BI2SR2CACU2O8 - OBSERVATION OF GAPLESS SUPERCONDUCTIVITY

被引：62

作者：

ISHIDA, K ^{[1
]}

KITAOKA, Y ^{[1
]}

ASAYAMA, K ^{[1
]}

KADOWAKI, K ^{[1
]}

MOCHIKU, T ^{[1
]}

机构：

[1] NATL RES INST MET, TSUKUBA, IBARAKI 305, JAPAN

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 1994年 / 63卷 / 03期

关键词：

BI2SR2CACU2O8; CU NQR AND NMR; T1; KNIGHT SHIFT;

D O I：

10.1143/JPSJ.63.1104

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The normal and superconducting properties in single crystal Bi2Sr2CaCu2O8 (Bi2212) with T(c) = 86K have been investigated by systematic measurements of the Cu-63 Knight shift, 63K(T) and the nuclear-spin-lattice relaxation time, T1. In the normal state, the T-dependences of 63K(T) and (T1T)-1 in Bi2212 share similar magnetic behaviors to the underdoped systems such as oxygen deficient YBa2Cu3O6+x and YBa2Cu4O8, namely, 63K(T) decreases with lowering temperature and 63(T1T)-1 has a peak above T(c). However, from the analyses of the anisotropy of 1/T1 and the hyperfine field, Bi2212 is found to belong to the slightly over-doped region as in Tl2Ba2CuO6+x and TlSr2CaCu2O8-x. In the superconducting state, the finding of T1T = const. law far below T(c) has revealed that the superconductivity is in a gapless regime, accompanied by the finite density of states at the Fermi level.

引用

页码：1104 / 1113

页数：10

共 49 条

[1]

ABRAGAM A, 1961, PRINCIPLES NUCLEAR M

[2] NMR-STUDY OF HIGH-TC SUPERCONDUCTORS [J].