A new process with a potential to rapidly texture bulk YBa₂Cu₃O_x superconductor

A new process has been developed to texture bulk YBa₂Cu₃O_x superconductors at temperatures about 100°C below the peritectic temperature. The texture is achieved in this process by directional recrystallization of compacts fabricated from quenched YBCO powders. Isothermal recrystallization of quenched precursors at 890°C for 3 min is found to result in the formation of more than 75% of YBa₂Cu₃O_x phase without any Y₂BaCuO₅. Recrystallization at higher temperatures leads to rapid formation of fine Y₂BaCuO₅ precipitates in addition to YBa₂Cu₃O_x. The formation of YBa₂Cu₃O_x increases with increasing heating rates. Directional recrystallization at 10 mm/h results in a well-textured microstructure with the YBa₂Cu₃Ox grains oriented parallel to the sample length. The magnetic field dependence of the critical current density at 77K of the directionally recrystallized material compares well with that of melt-textured YBCO and is superior to that of magnetically aligned and sintered YBCO.