Ultrafine MgO particles were introduced into Bi2Sr2Ca2Cu3O10/Ag (Bi-2223/Ag) tapes fabricated by the standard powder-in-tube (PIT) process. It was found that the phase transformation rate is decreased with increasing MgO concentration, Slight degradation of Bi-2223 formation rate is suggested to be of advantage for grain connectivity and grain alignment, Excessive doping and high sintering temperature resulted in bad transport properties due to severe agglomeration of MgO particles and the growth of residual secondary phase. The critical current was improved from 17 A for undoped sample to nearly 27 A for 1 wt% MgO doped sample heat-treated at 835 degrees C and/or 839 degrees C. The results of J(c)-B measurements show that the ultrafine MgO particles, as additional flux pinning centers, may strengthen flux pinning effectively. (C) 1997 Elsevier Science B.V.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%