The alignment of Bi(Pb)-Sr-Ca-Cu-O near the Ag-(Bi(Pb)-Sr-Ca-Cu-O) interface in silver-sheathed multifilamentary Bi(Pb)_2Sr_2Ca_2Cu_3O

摘要

The Ag-(Bi(Pb)-Sr-Ca-Cu-O (BSCCO)) interface region has been studied by scanning electron microscopy and transmission electron microscopy to a distance of 2 μm away from the silver in the Ag-sheathed multifilamentary Bi(Pb)_2Sr_2Ca_2Cu_3O (Bi(Pb)-2223) tapes. Owing to undulation of the silver surface, silver was found to play an important but not always positive role in the alignment of BSCCO grains. Based on the kink angle variation, the effective thickness of multifilamentary Bi(Pb)-2223 tapes capable of carrying a large current has been defined. We believe that the difference in effective thickness is the key reason leading to different critical current densities J_c for these tapes.