Detailed study of the effect of Ag on creep sintering and texturing of YBa₂Cu₃O_{7- delta}

Abstract

A detailed study has been carried out by several complementary techniques to clarify the role of Ag addition in creep sintering and texturing of YBCO. It is shown that, for specimens sintered in air under an applied load, at temperatures below 930°C. the addition of between 1 and 10% Ag does not improve the superconducting properties of the material, but rather it deteriorates them. This result is d u e mainly to (i) the fact that Ag enters into a liquid phase with Cu a n d 0 and induces a Cu deficiency in the ceramics and (ii) t h e orientation of Ag-YBCO interfaces decreases the degree of texture. A s a direct consequence of the existence of the liquid phase, Ag foils appear to be a good choice to use as contact foils during sintering. Furthermore. their presence helps reoxygenation of the material 1. introduction