Synthesis of bismuth-strontium-calcium-copper oxide powders for silver composite wires with uniform micron sized filaments

A chemical precipitation method is utilized to synthesize bismuth-strontium-calcium-copper oxide powder. Tetra-methyl ammonium hydroxide and tetra-methyl ammonium carbonate are used as a precipitant and for pH adjustment. Effect of processing parameters like carbonization time, and cation solution concentration on Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/ (Bi-2212) powders is reported. Powders with different particle size and distribution are used to fabricate Ag sheathed multifilamentary Bi-2212 round wires with diameter about 0.06 cm (corresponding to filament diameter about 3 /spl mu/m). Significant sausaging was observed for wires processed with larger particle size powders. Good filament uniformity was observed for wires produced from finer powders.