High pressure oxygenation in melt textured NdBa/sub 2/Cu/sub 3/O/sub 7/: identification of pinning mechanisms

A competing effect inducing both an enhancement of interface pinning and aging of the critical currents has been established in NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///Nd/sub 4/Ba/sub 2/Cu/sub 2/O/sub 10/ (Nd123/422) melt-textured ceramic composites upon high oxygen pressure annealing. It is suggested that Nd123/422 interfaces are enriched in antisite defects, which are properly oxygenated only upon high PO/sub 2/ annealing. Additional evidence for the enhanced oxygenation is gained from the observation of a consequent decrease of the field induced anomaly at intermediate fields.