Plastic deformation in high critical current melt‐textured YBa2Cu3O7

The effect of high‐temperature creep under different conditions in melt‐textured YBa2Cu3O7–Y2BaCuO5 composites, with high critical currents before deformation, is investigated. Transmission electron microscopy studies show that the low‐temperature oxygenation process causes a strong modification of the as‐deformed microstructure and leads to a clear degradation of the superconducting performances. This behavior of the superconducting properties is well correlated with the formation of extended planar defects such as large stacking faults and microcracks that severely diminish the vortex cutting length, thus enhancing the thermal activation effects on the critical currents and the irreversibility line.