Preferred orientation of Y2BaCuO5 particles entrapped by melt-textured YBa2Cu3O7-delta crystals

This study is an attempt to understand the orientation relationships between Y2BaCuO5 (Y211) inclusions and YBa2Cu3O7-delta (Y123) matrix in a melt growth sample. The Y123 crystals were grown by the constant undercooling method with top seeded growth using a nominal composition of Y123 + 0.4Y211 + 0.5wt%Pt. It was revealed that the Y211 particles tended to be oriented in the Y123 crystals and that the preferred orientation depended on the degree of undercooling (i.e. growth rate of Y123), the growth direction of Y123 and the shape of Y211 particles. The tendency was significantly observed in the Y123 crystal grown under the growth condition which caused pushing phenomenon of Y211 particles. The orientation relationship could be qualitatively explained by the prevalent trapping/pushing theory considering the peritectic reaction as well as the anisotropy of interfacial energy and geometry of Y211 particles.