GRAIN ALIGNMENT IN BULK YBA2CU3OX SUPERCONDUCTORS BY ISOTHERMAL PERITECTIC REACTION PROCESS

An isothermal peritectic reaction (IPR) process has been developed to fabricate YBa2Cu3Ox (123) superconductors with aligned grain structure in a relatively short time without a temperature gradient. The proces s consists of the preparation of Y2BaCuO5 (211) powder compact in wire form and infiltration of a Ba-Cu-O glass melt into the 211 compact be low the peritectic temperature of approximately 1010-degrees-C. During the infiltration at 965-degrees-C the 123 phase forms at the surface of the compact by the reaction between 211 grains and the glass, and t he newly formed 123 grains grow directionally towards the center of th e compact. The result of the infiltration is an aligned grain structur e with a preferred orientation of {100} planes in the axial direction of wire-type compacts. These 123 superconductor specimens show the zer o resistance (T(c)) at 92 K and transport critical current density (J( c)) of up to 1500 A/cm2. By this process, superconductor wires can be produced at shorter times and lower temperatures than the melt-texturi ng methods.