To determine intrinsic properties of the newly discovered Bi-Ca-Sr-Cu-O high Tc superconductors, single crystals are necessary. Compositions in this system have been heat treated to survey the melting temperatures and phase field in which superconductivity is detected. The nucleation and growth of the 85 K phase from the melted composition Bi4Ca3Sr 3Cu4O16+x is observed to be a kinetically slow process which can be precluded by a sufficiently rapid quench, but post-anneals produce the 85 and 110 K phases in the quenched material. The melted composition (23% Bi2O3-46% CaO,SrO-31% CuO), after subsequent slow cooling, results in large discrete crystals of the 85 K superconducting phase and a residual flux.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)