3-DIMENSIONAL DISLOCATION SUBSTRUCTURE IN NDBA2CU3OY

A three dimensional dislocation substructure is reported by transmissi on electron microscopy in an as-grown directionally solidified (rare e arth) Ba2Cu3Oy superconductor. Dislocations with a near or perfect [00 1] orientation and Burgers vectors lying on the basal plane are found to glide on (010) and {110}. A model is proposed in which cubic-like g lide is achieved through the formation of a track of Nd-->Ba antisites along the path swept by the dislocations. This finding can be correla ted with the enhanced flux pinning under H parallel to[001] observed i n these materials. (C) 1998 American Institute of Physics. [S0003-6951 (98)01144-9]