Superconductivity at 31 K in Alkaline Metal—Doped Cobalt Oxides

作     者：WENHai-Hu YANGHia-Peng LUXi-Feng YANJing 

作者机构：NationalLaboratoryforSuperconductivityInstituteofPhysicsandCenterforCondensedMatterPhysicsChineseAcademyofSciencesPOBox603Beijing100080 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2003年第20卷第5期

页      面：725-728页

核心收录：

学科分类：080705[工学-制冷及低温工程] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070205[理学-凝聚态物理] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0704[理学-天文学] 070301[理学-无机化学] 0702[理学-物理学] 

基　　金：国家自然科学基金 国家科技部项目 中国科学院知识创新工程项目 

主　　题：氧化钴 超导电性 掺杂 反磁性 磁滞现象 超顺磁性 碱金属掺杂 

摘      要：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).