Effects of deformation on current-limiting factors in Ag/BiSCCO tapes

I-V characteristics, transport critical current density J(c) at 77 K in mod erate magnetic fields and irreversibility fields were measured in Ag/BiSCCO -2223 tapes at various stages of the OPIT process. intermediate deformation dramatically reduces I-c in as-deformed state while retaining a finite-siz e percolative channel for transport current after used pressing load up to 11 GPa. The channel has a similar fraction of strong links (45%) and vortex pinning characteristics as those in a non-deformed state. Combination of i ntermediate deformation with subsequent sintering improves pinning characte ristics of the tapes, reasonably increases vortex-glass-vortex-liquid cross over field H-g and significantly accelerates I-c growth during subsequent t hermal processing. (C) 1998 Published by Elsevier Science B.V. All rights r eserved.