INVESTIGATION OF PHASE AND TEXTURE EVOLUTION DURING THERMOMECHANICAL PROCESSING IN BI(PB)-2223 AG TAPES BY HIGH-ENERGY SYNCHROTRON X-RAY DIFFRACTION/

High energy synchrotron X-ray diffraction has been successfully used t o observe the phase and c-axis texture evolution during thermomechanic al processing in Bi(Pb)-2223/Ag tapes. The c-axis texture of the 2212 phase formed rapidly during the first heating ramp. The phase conversi on to 2223 and associated texture development was nearly complete afte r the second stage of sintering/deformation, although several more sta ges were required to achieve a high critical current density. It has b een found that the 2201 phase forms during the initial two stages of s intering/deformation. The observed decrease in 2201 phase content duri ng the subsequent cycles is believed to contribute directly to the sig nificant improvement in the critical current density. (C) 1998 Elsevie r Science B.V. All rights reserved.