EFFECT OF AG ON PROCESSING AND PROPERTIES OF BI AND TL-BASED HTSC MATERIALS

High temperature x-ray diffraction was used to determine the effect of Ag on the peritectic melting sequence of low carbon content Bi2Sr2CaC u2O8. Only slight changes in the solid solution compositions were foun d with 20 wt.% Ag added to the system, with the phases and stability r egions remaining the same. Microstructure, sintering behavior, lattice parameters, and superconducting property changes in Tl0.5Pb0.5Sr2CaCu 2O7 were investigated with different amounts of Ag added to investigat e the effect of Ag. From the results in both systems, the presence of Ag does not seem to change the intrinsic properties of these supercond uctors, but affects the processing variables, like reaction temperatur es, which change the optimum temperatures for obtaining best propertie s. The temperature at which melting occurs and the amount of liquid fo rmed depends both on the amount of Ag and carbon content of the materi als.