Superconductivity in a layered cobalt oxyhydrate Na$_{0.31}$CoO$_{2}\cdot$1.3H$_{2}$O

Guanghan Cao; Chunmu Feng; Yi Xu; Wen Lu; Jingqin Shen; Minghu Fang; Zhu'an Xu

doi:10.1088/0953-8984/15/33/102

paper

Superconductivity in a layered cobalt oxyhydrate Na $_{0.31}$ CoO $_{2} \cdot$ 1.3H $_{2}$ O

arXiv:cond-mat/0305503 · doi:10.1088/0953-8984/15/33/102

Abstract

We report the electrical, magnetic and thermal measurements on a layered cobalt oxyhydrate Na $_{0.31}$ CoO $_{2} \cdot$ 1.3H $_{2}$ O. Bulk superconductivity at 4.3 K has been confirmed, however, the measured superconducting fraction is relatively low probably due to the sample's intrinsic two-dimensional characteristic. The compound exhibits weak-coupled and extreme type-II superconductivity with the average energy gap $Δ_{a} (0)$ and the Ginzburg-Landau parameter $κ$ of $\sim$ 0.50 meV and $\sim$ 140, respectively. The normalized electronic specific heat data in the superconducting state well fit the $T^{3}$ dependence, suggesting point nodes for the superconducting gap structure.

4 pages, 3 figures

Superconductivity in a layered cobalt oxyhydrate Na0.31​CoO2​⋅1.3H2​O

Abstract

Superconductivity in a layered cobalt oxyhydrate Na $_{0.31}$ CoO $_{2} \cdot$ 1.3H $_{2}$ O