MICROSTRUCTURE OF AG BI(PB)-2223 TAPES PREPARED BY SOLID-STATE REACTION/

The processing of Ag/Bi(Pb)-2223 tapes via the prevailing solid state reaction was investigated. precursor powder of the composition Bi1.86P b0.26Sr1.96Ca1.95CU2.97O10+delta containing mainly Bi-2223 phase was e mployed. Particular attention was devoted to the microstructural prope rties of the tapes subjected to rolling and subsequent heat treatment in one, two, and three steps, respectively. A sharp texturing gradient exists in the superconducting cores, and the repeated treatment leads to deterioration of the superconducting properties. The latter effect is ascribed to the formation of periodic defects arising during the r epeated rolling of the sintered superconducting core.