Y2BaCuO5 Segregation in YBa2Cu3O(7-x) During Melt Texturing

摘要

A three dimensional structure model of the Y2BaCuO5 (211) particle segregation in YBa2Cu3O(x) (123) domains was developed. A model of 211 particle segregation on three sets of mutually intersecting 110 type of planes in 123 domains was proposed which can be used to generate 211 particle tracks similar to those observed in polished microstructures. Studies were performed on Y123 rods through zone melt processing. Fine 211 was pushed to the periphery of the sample rod at speeds where a planar (or faceted) growth front could be maintained. Extensive studies were performed on BaCeO3 doped Y123 samples. It was found that BaCeO3 particles build up at the interface between the growing crystal and the liquid separating the 211 in the melt (which is the source of the Y atoms required for Y-123 growth) from the Y123 growth front. In samples with elevated levels of BaCeO3 (10 wt) additions, the BaCeO3 particles clustered into bands resulting from periodic trapping of the particles at the solidification front.