【摘要】 将化学计量比为 1∶2的Mg粉和B粉直接装管 ,采用原位粉末套管 (PIT)技术制备了MgB2 /Fe线材 ,在四个温度条件下 (650℃ ,750℃ ,850℃ ,950℃ )进行了热处理 .采用四引线法测量了不同温度和磁场下线材的临界电流密度 (Jc) ,分析了热处理温度对磁通钉扎的影响 ,采用扫描电镜 (SEM)和透射电镜 (TEM)研究了线材中MgB2 超导相的微观结构 .结果表明 :热处理温度对MgB2 /Fe线材的Jc 和磁通钉扎特性有显著影响 ,最佳热处理温度应为 750℃ .更多还原

【Abstract】 Dense and single phase MgB-2/Fe superconducting wires have been successfully fabricated by the in-situ powder-in-tube (PIT) technique, in which an Mg2B mixture was used as the starting material. As for the effect of heat treatment on the MgB-2 phase, we prepared MgB-2/Fe wires under four annealing temperatures (650℃, 750℃, 850℃, 950℃). A comparative study of the critical current density and flux pinning in wires was performed by direct four point transport measurements at different temperature in magnetic field. And the MgB-2 microstructure was studied by scanning electron microscopy and transmission electron microscopy. The results show that the annealing temperature has an important effect on the critical current and flux pinning force of MgB-2/Fe wires and the optimal annealing temperature is 750℃.更多还原