Fast growth of Bi2Sr2Ca2Cu3O10+x and Bi2Sr2CaCu2O8+x thin crystals at the surface of KCl fluxes

Abstract
We report a novel technique to grow crystals of the high‐temperature superconductor Bi2Sr2Ca2Cu3O10+x and Bi2Sr2CaCu2O8+x (2223 and 2212 BSCCO phases), both pure and Pb substituted. The technique, based on chemical transport in a thermal gradient in molten KCl, is simple and inexpensive, and yields a continuous output of crystals, with growth times of a few minutes, i.e., orders of magnitude shorter than conventional flux methods. Depending on melt aging, crystals of either the pure 2223 or the pure 2212 BSCCO phases are obtained, having zero‐resistance temperature of 105 and 90 K, respectively, and a transport critical current density of 104 A cm−2 at liquid nitrogen temperature.