Na掺杂对Bi-2212高温超导体性能的影响  

Influences of Na Doping on Superconducting Properties of Bi-2212 High Temperature Superconductors

作　　者：张胜楠[1] 马小波[1] 崔利军 黄英健 李成山[1] 冯建情[1] 闫果 张平祥[1,2] Zhang Shengnan;Ma Xiaobo;Cui Lijun;Huang Yingjian;Li Chengshan;FengJianqing;Yan Guo;Zhang Pingxiang(Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China;Western Superconducting Technologies Co.,Ltd,Xi'an 710018,China;Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]西部超导材料有限公司,陕西西安710018 [3]西安理工大学,陕西西安710048

出　　处：《稀有金属材料与工程》2020年第4期1184-1190,共7页Rare Metal Materials and Engineering

基　　金：National Science Foundation of China(51472206);National ITER Program of China(2013GB110001);National Key Research and Development Program of China(2017YFB0902303)。

摘　　要：采用放电等离子烧结(SPS)工艺制备了Na掺杂的Bi2.1Sr1.96Ca1-xNaxCu2.0O8+δ超导材料。Bi-2212前驱体粉末采用改进的共沉淀工艺制备,并在烧结前将前驱体粉末与NaOH混合。研究了Na离子掺杂对Bi-2212体系晶格结构、相组成、微结构和相关超导性能的影响。结果表明:Na离子掺杂导致Bi-2212体系相转变温度的显著降低,因此在SPS过程中,烧结温度相应发生了变化。但Na掺杂仍然导致大量Bi2Sr2CuO6(Bi-2201)相生成,进而导致了超导相含量的降低和织构度的破坏,所以给体系的超导电性带来了负面的影响。另一方面,Na掺杂相Bi-2212中掺入了大量的点缺陷,这些点缺陷可以作为有效钉扎中心。因此,通过优化Na掺杂Bi-2212的烧结工艺,可在高场条件下获得体系性能的改善。Polycrystalline bulks Bi2.1Sr1.96Ca1-xNaxCu2.0O8+δ(Bi-2212)with Na doping content of x=0,0.02,0.05,0.10(at%)were fabricated by spark plasma sintering(SPS)process.The Bi-2212 precursor powders were synthesized by modified co-precipitation process,and NaOH powders were added as dopants before calcination.The influences of Na+ion doping on lattice parameters,phase composition,microstructures as well as related superconducting properties were investigated.The results show that introduction of Na in Bi-2212 system can cause an obvious decrease in phase transition temperatures.Thus during the SPS process,although the sintering temperature is greatly decreased,Na doped Bi-2212 bulks still tend to decompose into Bi2Sr2CuO6(Bi-2201)phase,which leads to the decrease of both superconducting phase content and texture degrees,thus causing negative effects on superconducting properties.In addition,Na doping introduces more point defects into Bi-2212 matrix,which act as flux pinning centers during current transport process,and contribute to the increase in current capacity under high field.Therefore,Na doping with optimized sintering parameters should be considered as a promising method to enhance the high field current capacity of Bi-2212 system.

关 键 词：高温超导材料 化学掺杂 涡旋钉扎机制 临界电流密度 

分 类 号：TB34[一般工业技术—材料科学与工程]