Field-induced pinning centers of YBa2Cu3O7-y superconducting thick film prepared by liquid phase epitaxy

Superconducting YBa2Cu3O7-y films were fabricated by liquid phase epitaxy (LPE) on MgO (100) and NdGaO3 (110) single-crystalline substrates. The film of 10 mu m thickness on the MgO substrate shows a high critical current density over 10(5) A/cm(2) at 77.3 K. This film includes the stacking faults that were introduced due to the large lattice mismatch between the YBCO film and the MgO substrate. We measured J(c)-B characteristics of this high J(c) and found the peak effect: enhancing J(c) with increasing field. On the other hand, J(c) of the films on the NdGaO3 substrate is comparably low, and we have a microstructure without stacking faults. These results suggest that the stacking faults in the films on MgO substrates behave as field-induced pinning centers at 77.3 K.