Defects near the Y2BaCuO5/YBa2Cu3O(7-x) interface and their effect on flux-pinning in melt- processed and quench-melt-growth processed YBa2Cu3O(7-x)

摘要

A detailed examination of the Y(sub 2)BaCuO(sub 5) (211)/YBa(sub 2)Cu(sub 3)O(sub 7-x) (123) interface in several melt-processed 123 samples prepared using different methods was undertaken using analytical electron microscopy. It is found that there exists a significant increase in the a-b planar stacking fault density in 123, near the 211/123 interface. When viewed along (001), these faults appear as disks with diameter from a few to 30 nm and are bounded by dislocation loops. Most stacking faults are confined to the (001) basal plane. The size and density of defects around the 211 particles suggest that these defects could act as effective flux-pinning sites and may explain the observations of increased J(sub c) with increasing volume fraction of 211 and a maximum in J(sub c) when the applied field parallel to the c-axis. 16 refs.