Preparation of highly textured Tl(1223)/Ag superconducting tapes

High-purity Tl(1223) ceramics have been produced by a reaction under high isostatic gas pressure (50 bar). A new method of synthesis consisting in a two-step reaction involving substantial melting at very high temperature (up to 1100/spl deg/C) produced well-shaped plate-like grains. An electrophoretic deposition (ED) technique then was used to produce uniform layers of controlled thickness on Ag ribbons. By alternating ED and uniaxial pressing, a high degree of c-axis texture, comparable with the one generally observed for Bi-based tapes, was obtained thanks to the appropriate grain morphology of the ceramic that had been synthesized by the two-step reaction. After annealing, critical current densities up to 11,000 A/cm/sup 2/ were reached. Despite the fact that the transport properties are still dominated by weak links, some important obstacles-in particular difficulties in phase formation and in texturing-have been overcome, indicating that Tl(1223) remains a promising material for large scale high-T/sub c/ superconductor applications.