Fabrication of dense Ba sub 2 YCu sub 3 O sub (7-delta) superconductor wire by molten oxide processing.

Fabrication of high T sub c ceramic superconductors by an oxide melting method in place of conventional sintering method has been attempted. Using three different processes, i.e., melt- drawing, melt-spinning, or preform-wire melting, it is demonstrated that the Ba sub 2 YCu sub 3 O sub (7-delta) type superconductors can successfully be fabricated into a desired geometry such as wire and ribbon. T sub c's for R=O were about 92K. The density of the melt-processed compound was measured to be as high as 6.2 g/cm, or ~98% of the theoretical density 6.3 g/cm as compared to the value of 80~85% density for sintered samples. The increased density is likely to be responsible for the noted improvements in fracture resistance and in the J sub c value of the melt-processed compound.