YBa_2Cu_3O_(7-x)纳米单晶超导性和室温铁磁性研究  

The Superconductivity and Room Temperature Ferromagnetism of YBa_2Cu_3O_(7-x) Nanosize Single Crystal

作　　者：沈振江[1,2] 邴丽娜[1] 陈万平[2] 王雨[2] 陈王丽华[2] 江向平[3] 

机构地区：[1]海南师范大学物理与电子工程学院,海南海口571158 [2]香港理工大学应用物理系 [3]景德镇陶瓷学院材料科学与工程学院,江西景德镇333403

出　　处：《陶瓷学报》2014年第6期573-576,共4页Journal of Ceramics

基　　金：国家自然科学基金项目(编号:11304069);海南省自然科学基金项目(编号:114009);海南省高等学校科学研究项目(编号:Hjkj2013-24);海南师范大学拟建物理学硕士点项目(编号:20130282202&20140092102)

摘　　要：采用软化学法制备了YBa2Cu3O7-x(YBCO)纳米单晶,并与利用传统固相法制备出YBCO陶瓷粉末作对比。性能测试表明:YBCO纳米单晶的晶体结构为具有高结晶度和良好单相性的正交对称钙钛矿结构,其具有200 nm-500 nm的粒度尺寸和很好的单晶结构,其高温超导性具有超导转变温度低、转变温度区间宽、电阻大等性能,此外其还表现出了一定的室温铁磁性,这是由YBCO纳米单晶的小尺寸效应、相滑移机制、高表面离子缺陷浓度、特殊的单晶表面性质等引起的。YBa_2Cu_3O_7-x single crystal in nanosize was successfully synthesized via soft chemical method. A group of YBCO ceramic powders were also prepared by traditional solid reaction method for comparison. Results show that YBa_2Cu_3O_7-x nanosize single crystal is of a single perovskite structure phase with an orthorhombic symmetry and high crystallinity. The TEM images show that its particle sizes are 200 nm-500 nm. Besides, it shows high temperature superconductivity with novel aspects, such as lower critical temperature, broader transition temperature area and higher resistance. Furthermore, unconventional room temperature ferromagnetism was also detected. Nanosize, phase slip mechanism, high ion-induced surface defect concentration and novel surface properties generated by the special structure of the nanosize single crystal were considered as the reasons.

关 键 词：YBa_2Cu_3O_7-x纳米 单晶 超导性 室温铁磁性 

分 类 号：TQ174.75[化学工程—陶瓷工业]