Fabrication of dense Ba2YCu3O7−δ superconductor wire by molten oxide processing

Abstract

Fabrication of high T_c ceramic superconductors by an oxide melting method in place of a 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 Ba₂YCu₃O_7−δ type superconductors can successfully be fabricated into a desired geometry such as wire and ribbon. T_c’s for R=0 were about 92 K. The density of the melt‐processed compound was measured to be as high as 6.2 g/cm³, or ∼98% of the theoretical density 6.3 g/cm³ 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_c value of the melt‐processed compound.