DIRECTIONAL ISOTHERMAL GROWTH OF HIGHLY TEXTURED BI2SR2CACU2OY

For Bi2Sr2CaCu2Oy (2212), it is shown that an oxygen gradient, as oppo sed to a temperature gradient, can be used to produce large bulk forms of the 2212 superconductor with highly textured microstructures from an oxygen-deficient melt held at a constant temperature. Material prod uced in this manner was found to have transition temperatures between 85 and 92 K, high critical current densities below 20 K, and modest cr itical current densities at 77 K.