Microstructure and Jc property on the Bi-2223 bulk prepared by inserting Ag layers

The microstructure and critical current density ( J c) property of (Bi,Pb) 2Sr 2Ca 2Cu 3O y (Bi-2223)/Ag multi-layered bulks were investigated. They were prepared by stacking Ag sheets alternately into the oxide, and then sintered at 840°C for 10–50 h. From the XRD and SEM results, high c-axis alignment and dense structure of Bi-2223 plate-like grains were observed near the region of the interface between Bi-2223 layer and Ag sheet, and the other regions in the oxide were random and porous structures. Further, we measured J c value using the four-probe method at 77 K and self-field. J c values of the multi-layered bulk were improved in proportion to increasing the number of Ag sheets and the maximum J c is estimated to be 320 A/cm 2 in the sample with four Ag sheets. We thought that improvement of J c performance was caused by highly c-axis aligned and densely structured region formed by Ag sheets.