Oxidation state of cobalt in the NaxCoO2-δ•γH2O superconductor

被引：50

作者：

Karppinen, M ^{[1
]}

Asako, S ^{[1
]}

Motohashi, T ^{[1
]}

Yamauchi, H ^{[1
]}

机构：

[1] Tokyo Inst Technol, Mat & Struct Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan

来源：

CHEMISTRY OF MATERIALS | 2004年 / 16卷 / 09期

关键词：

D O I：

10.1021/cm035298h

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Here we present results of accurate wet-chemical redox analyses revealing that the oxidation number of cobalt in the newly discovered CoO2-layer superconductor, NaxCoO(2)(.) yH(2)O (x approximate to 0.36, y approximate to 1.3) is similar to3.46. This value is significantly lower than the one (similar to3.64) expected on the basis of the value determined for the Na to Co stoichiometry ratio, x. The "lower-than-expected" value for the Co oxidation state may be alternatively explained by the presence of oxygen vacancies or excess protons. Moreover, the result implies that rather than an electron-doped Co-IV lattice the phase should be considered as a hole-doped Co-III lattice.

引用

页码：1693 / 1696

页数：4

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