Role of doping and dimensionality in the superconductivity of NaxCoO2

被引：36

作者：

Bañobre-López, M

Rivadulla, F ^{[1
]}

Caudillo, R

López-Quintela, MA

Rivas, J

Goodenough, JB

机构：

[1] Univ Santiago de Compostela, Dept Chem Phys, Santiago De Compostela 15782, Spain

[2] Univ Santiago de Compostela, Dept Appl Phys, Santiago De Compostela 15782, Spain

[3] Univ Texas, Texas Mat Inst, Austin, TX 78712 USA

来源：

CHEMISTRY OF MATERIALS | 2005年 / 17卷 / 08期

关键词：

D O I：

10.1021/cm0500760

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：

We report a complete analysis of the formal Co3+/(4+) oxidation state in NaxCoO2, in the interval 0.31 <= x <= 0.69. lodometric titration and thermoelectric power confirm that a direct relationship between the Na content and the amount of Co3+ cannot be established in this system. Creation of a significant amount of oxygen vacancies accompanies Na-ion deintercalation, keeping the formal Co valence at 3.45+ for x <= 0.45. In light of new thermoelectric power data which reveals important differences between the hydrated (superconducting) and nonhydrated (nonsuperconducting) samples, we propose here that water plays an important "chemical" role beyond that of a spacer between the CoO2 layers.

引用

页码：1965 / 1968

页数：4

共 17 条

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