Flux growth of superconducting single crystals in the Bi-Sr- Ca-Cu-O system.

We report the growth of single crystals of high T sub c superconductors in the Bi-Sr-Ca-Cu-O system from alkali halide fluxes. Crystals grow as very thin black platelets with cm sup 2 surface areas and have nominal composition Bi sub (2.2) Sr sub 2 Ca sub (0.8) Cu sub 2 O sub (8+delta). A classical, high-temperature solution approach to crystal growth, this technique should permit regulation of crystal size and quality by control of growth parameters including cooling rate and melt composition. Electrical and magnetic measurements confirm superconductivity. The major transition occurs at ~81K, but some samples show evidence for a small superconducting fraction with a T sub c of ~115K.