Superconductivity at 31 K in Alkaline Metal-Doped Cobalt Oxides
WEN Hai-Hu, YANG Hai-Peng, LU Xi-Feng, YAN Jing
National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100080
Superconductivity at 31 K in Alkaline Metal-Doped Cobalt Oxides
WEN Hai-Hu;YANG Hai-Peng;LU Xi-Feng;YAN Jing
National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100080
Abstract： By using a simple solid reaction method, we have fabricated alkaline metal doped cobalt oxides AnxCoO2+δ (An = Na, K). The magnetic measurement shows a superconducting-like diamagnetic signal at 31 K based on a strong superparamagnetic signal. Below 31 K, the magnetization hysteresis loops contain a strong rough linear superparamagnetic background and a superconducting hysteresis. The typical magnetization hysteresis loops for a type-II superconductor are found. Preliminary resistive data also show a fast dropping of resistance below Tc. These give indication of superconductivity below 31 K in AnxCoO2+δ (An = Na, K).
WEN Hai-Hu;YANG Hai-Peng;LU Xi-Feng;YAN Jing. Superconductivity at 31 K in Alkaline Metal-Doped Cobalt Oxides[J]. 中国物理快报, 2003, 20(5): 725-728.
WEN Hai-Hu, YANG Hai-Peng, LU Xi-Feng, YAN Jing. Superconductivity at 31 K in Alkaline Metal-Doped Cobalt Oxides. Chin. Phys. Lett., 2003, 20(5): 725-728.
2003, Vol. 20 
