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Unconventional superconductivity in NaxCoO2 yH2O

H. Sakurai·K. Takada·T. Sasaki·E. Takayama-Muromachi
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Abstract

We synthesized powder samples of Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O changing the volume of the water in the hydration process, then investigated their superconducting properties,. It was proved that the volume of water is one of key parameters to obtain a single phase of Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O with good superconducting properties. The transition temperature, $T_{c}$, of the sample changed gradually while it was stored in the atmosphere of 70% humidity. Superconducting behavior under high magnetic field was very sensitive to $T_{c}$. $H_{c2}$ of a high quality sample with high $T_{c}$ seemed very high.

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H. Sakurai, K. Takada, T. Sasaki, E. Takayama-Muromachi. 2004-08-19. Unconventional superconductivity in NaxCoO2 yH2O. https://doi.org/10.1016/j.physc.2004.12.017

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