59Co-NMR knight shift of superconducting NaxCoO2•yH2O

被引:76
作者
Kobayashi, Y [1 ]
Yokoi, M [1 ]
Sato, M [1 ]
机构
[1] Nagoya Univ, Dept Phys, Div Sci Mat, Chikusa Ku, Nagoya, Aichi 4648602, Japan
关键词
NaxCoO2 center dot yH(2)O; superconductivity; NMR; knight shift;
D O I
10.1143/JPSJ.72.2453
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Layered Co oxide NaxCoO2.yH(2)O with the superconducting transition temperature T-c = 4.5 K has been studied by Co-59-NMR. The Knight shift K estimated from the observed spectra of a powder sample exhibits almost temperature (T)-independent behavior above T-c and decreases with decreasing T below T-c. This result and the existence of the coherence peak in the spin-lattice relaxation rate versus T curve reported by the present authors indicate, naively speaking, that the singlet order parameter with s-wave symmetry is realized in NaxCoO2.yH(2)O. Differences in the observed behaviors between the spectra of a nonaligned sample and those of an aligned sample embedded in epoxy adhesive by applying an external magnetic field are discussed.
引用
收藏
页码:2453 / 2455
页数:3
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