High critical currents in Ag-BSCCO(2223) tapes : are the grain boundaries really weak-links ?

Abstract The remarkable improvement of the superconducting properties of polycrystalline BSCCO(2223) when processed into Ag-clad tapes has been investigated with magnetisation measurements. The tape bulk critical current density has been compared directly with the intragrain critical current of the crystalline powder extracted from the tapes. The results show that two factors contribute to the excellent tape performance: Intragranular flux pinning is much stronger than might be expected from single crystal data, and the grain boundaries display no evidence of being ‘weak-links’.