59Co NQR study on superconducting NaxCoO2.yH2O
59Co NQR study on superconducting NaxCoO2.yH2O
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超导NaxCoO2.yH2O的59Co NQR研究
DOI：
10.1143/jpsj.72.2161
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发表时间：
2003
影响因子：
1.7
通讯作者：
M. Sato
中科院分区：
文献类型：
--
作者：
Y. Kobayashi;M. Yokoi;M. Sato
用59Co核磁共振研究了超导转变温度Tc=4.5K的层状Co氧化物NaxCoO2·yH2O。核自旋弛豫速率1/59T1与正常态的温度T几乎成正比。在超导态，当温度低于∼0.8Tc时，出现相干峰，且随T的降低而减小。对NaxCoO2·yH2O和NaxCoO2的1/T1T值和磁化率的详细比较表明，前者的金属状态比后者更接近铁磁性相。这些实验结果限制了超导电性的机制。
Layered Co oxide Na x CoO 2 · y H 2 O with a superconducting transition temperature T c =4.5 K has been studied by 59 Co NQR. The nuclear spin relaxation rate 1/ 59 T 1 is nearly proportional to temperature T in the normal state. In the superconducting state, it exhibits the coherence peak and decreases with decreasing T below ∼0.8 T c . Detailed comparison of the 1/ T 1 T values and the magnetic susceptibilities between Na x CoO 2 · y H 2 O and Na x CoO 2 implies that the metallic state of the former system is closer to a ferromagnetic phase than that of the latter. These experimental results impose a restriction on the mechanism of the superconductivity.