# Superconductivity in a layered cobalt oxyhydrate Na0.31CoO2·1.3H2O

@article{Cao2003SuperconductivityIA,
title={Superconductivity in a layered cobalt oxyhydrate Na0.31CoO2·1.3H2O},
author={Guanghan Cao and Chun-mu Feng and Yi Xu and Wen Lu and Jingqin Shen and Minghu Fang and Zhuang Xu},
journal={Journal of Physics: Condensed Matter},
year={2003},
volume={15}
}
• G. Cao, +4 authors Zhuang Xu
• Published 2003
• Chemistry, Physics
• Journal of Physics: Condensed Matter
We report the electrical, magnetic and thermal measurements on a layered cobalt oxyhydrate Na0.31CoO2·1.3H2O. 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 an average energy gap Δa(0) and a Ginzburg–Landau parameter κ of ~0.50 meV and 140, respectively. The temperature… Expand

#### References

SHOWING 1-10 OF 13 REFERENCES
Chemical instability of the cobalt oxyhydrate superconductor under ambient conditions
Abstract The layered sodium cobalt oxyhydrate superconductor Na0.3CoO2·1.4H2O is shown through X-ray diffraction and thermogravimetric studies to be one of the series of hydrated phases of Na0.3CoO2.Expand
Superconductivity in two-dimensional CoO2 layers
• Medicine, Chemistry
• Nature
• 2003
There is a marked resemblance in superconducting properties between the present material and high-Tc copper oxides, suggesting that the two systems have similar underlying physics. Expand
Electronic structure of NaCo 2 O 4
First principles density functional calculations of the electronic and magnetic properties of the layered oxide ${\mathrm{NaCo}}_{2}{\mathrm{O}}_{4}$ have been performed using the general potentialExpand
Phenomenological theory of unconventional superconductivity
• Physics
• 1991
This article is a review of recent developments in the phenomenological description of unconventional superconductivity. Starting with the BCS theory of superconductivity with anisotropic CooperExpand
Flux trapping and superconductive glass state in La/sub 2/CuO/sub 4-//sub y/:Ba
• Materials Science, Physics
• 1987
Susceptibility and magnetic-moment measurements from 1.9 to 35 K in magnetic fields up to 1.5 T in powder samples of La/sub 2/CuO/sub 4-//sub y/:Ba are reported. The diamagnetism observed in theExpand
UPPER‐CRITICAL‐FIELD LIMITS FOR BULK TYPE‐II SUPERCONDUCTORS
Approximate zero‐temperature upper‐critical‐field limits Hc20 (max), consistent with the recent extreme‐type‐II theory of Werthamer, Helfand, and Hohenberg (WHH), are deduced by assuming (1) anExpand
Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects
• Physics
• 1966
A previously obtained solution of the linearized Gor'kov equations for the upper critical magnetic field ${H}_{c2}$ of a bulk type-II superconductor is extended to include the effects of Pauli spinExpand
Cobalt oxide layers
The specific heat of $(\mathrm{N}\mathrm{a},\mathrm{C}\mathrm{a}){\mathrm{Co}}_{2}{\mathrm{O}}_{4}$ is measured at low-temperatures to determine the magnitude of the electronic specific-heatExpand
Since the discovery by Steglich et al. (1979) of superconductivity in the high-effective-mass ($\ensuremath{\sim}200{m}_{e}$) electrons in Ce${\mathrm{Cu}}_{2}$${\mathrm{Si}}_{2}$, the search for andExpand