Evaluation of techniques for fabricating very fine grained YBa/sub 2/Cu/sub 3/O/sub 7- delta /+Ag composites

The authors have compared several blending techniques to make Ag+YBa/sub 2/Cu/sub 3/O/sub 7- delta / (Y123) composites. A chemical precipitation route seems to give the best dispersion of the Ag but appears to cause some decomposition of the finer-grained fraction of the Y123. The lower intergranular porosity in these composites reduces the O/sub 2/ uptake in the samples, necessitating longer oxygen anneals. Long oxygen anneals for the composites can be avoided by first sintering the Y123 with an oxygen anneal and then blending in the Ag.