Proton incorporations and superconductivity in a cobalt oxyhydrate

Guanghan Cao; Xiaoming Tang; Yi Xu; Ming Zhong; Xuezhi Chen; Chunmu Feng; Zhu'an Xu

doi:10.1016/j.ssc.2004.04.034

paper

Proton incorporations and superconductivity in a cobalt oxyhydrate

arXiv:cond-mat/0402638 · doi:10.1016/j.ssc.2004.04.034

Abstract

We report the evidence of proton incorporations in a newly-discovered cobalt oxyhydrate superconductor. During the hydration process for Na $_{0.32}$ CoO $_{2}$ by the direct reaction with water liquid, it was shown that substantial NaOH was gradually liberated, indicating that H $^{+}$ is incorporated into the hydrated compound. Combined with the thermogravimetric analysis, the chemical composition of the typical sample is Na $_{0.22}$ H $_{0.1}$ CoO $_{2} \cdot 0.85$ H $_{2}$ O, which shows bulk superconductivity at 4.4 K.

9 pages, 4 figures