【摘要】 研究了名义化学成分为Bi2.10Sr1.96Ca1.0Cu2.00Ox的Bi-2212/Ag超导带材的制备和性能,采用X射线衍射技术和扫描电镜技术分析了Bi-2212相的合成过程和Bi-2212/Ag超导带材中超导体的微观组织形貌,在4.2～30K温度范围内测量了Bi-2212/Ag超导带材样品的临界电流密度(Jc),应用背景场的磁场(B)最高达到7T。结果表明,Bi2.10Sr1.96Ca1.0Cu2.00Ox的粉末在空气中多次烧结后,2212相生成量可以达到91.6%;Bi-2212/Ag超导带材中晶粒间有良好的连接性,但微观组织中仍存在大量的缩孔。在磁场高于5T和温度低于20K时,Jc随应用磁场和操作温度升高而缓慢下降,而当磁场小于5T和温度超过20K时,Jc快速下降。通过熔化-慢冷工艺得到的Bi-2212/Ag带材其临界电流密度Jc可达到320A/mm2(4.2K,7T)。更多还原

【Abstract】 The preparation and properties of Bi-2212/Ag tapes with a nominal chemical composition of Bi2.10Sr1.96Ca1.0Cu2.00Ox have been studied in this paper. The synthesis of Bi-2212 phase and the microstructure of Bi-2212/Ag tape have been analyzed by XRD and SEM. The critical currents density (Jc) has been measured in the temperature range from 4.2 K to 30 K in applied magnetic field (B) up to 7 T. The results show that the 2212 phase of 91.6% can be obtained in Bi2.10Sr1.96Ca1.0Cu2.00Ox powder sintered in air; good intergrain joints and more holes exist in the Bi-2212/Ag tapes. Jc decreases slowly with the increase of applied magnetic field over 5 T at an operation temperature below 20 K,whereas quickly below 5 T and over 20 K. The Jc value has been obtained to be 320 A/mm2 (4.2 K, 7 T) for the Bi-2212/Ag tapes by melting and slow cooling process in this study.更多还原