Superconducting Properties under Magnetic Field in Na$_{0.35}$CoO$_{2}{\cdot}1.3$H$_{2}$O Single Crystal

Takahiko Sasaki; Petre Badica; Naoki Yoneyama; Kazuyoshi Yamada; Kazumasa Togano; Norio Kobayashi

doi:10.1143/JPSJ.73.1131

paper

Superconducting Properties under Magnetic Field in Na $_{0.35}$ CoO $_{2} \cdot 1.3$ H $_{2}$ O Single Crystal

arXiv:cond-mat/0402355 · doi:10.1143/JPSJ.73.1131

Abstract

We report the in-plane resistivity and magnetic susceptibility of the layered cobalt oxide Na $_{0.35}$ CoO $_{2} \cdot 1.3$ H $_{2}$ O single crystal. The temperature dependence of the resistivity shows metallic behavior from room temperature to the superconducting transition temperature $T_{c}$ of 4.5 K. Sharp resistive transition, zero resistivity and almost perfect superconducting volume fraction below $T_{c}$ indicate the good quality and the bulk superconductivity of the single crystal. The upper critical field $H_{c 2}$ and the coherence length $ξ$ are obtained from the resistive transitions in magnetic field parallel to the c-axis and the $ab$ -plane. The anisotropy of $ξ$ , $ξ_{ab} / ξ_{c} =$ 12 nm/1.3 nm $≃$ 9.2, suggests that this material is considered to be an anisotropic three dimensional superconductor. In the field parallel to the $ab$ -plane, $H_{c 2}$ seems to be suppressed to the value of Pauli paramagnetic limit. It may indicate the spin singlet superconductivity in the cobalt oxide.

4 pages, 4 figures

References in corpus (1)

Unconventional Upper- and Lower-Critical Fields and Normal-State Magnetic Susceptibility of the Novel Superconducting Compound $N a_{0.35} C o O_{2} \cdot 1.3 H_{2} O$

Superconducting Properties under Magnetic Field in Na0.35​CoO2​⋅1.3H2​O Single Crystal

Abstract

References in corpus (1)

Cited by in corpus (3)

Superconducting Properties under Magnetic Field in Na $_{0.35}$ CoO $_{2} \cdot 1.3$ H $_{2}$ O Single Crystal