Abstract
Pushing/entrapment phenomenon of the high temperature stable phase, RE2BaCuO5 (RE211; RE=Y, Sm) during peritectic solidification of REBa2Cu3O7−δ (RE123) oxide superconductors was investigated. The RE123 crystals were grown at different undercoolings by isothermal solidification processing combined with the seeding method. In the Y-system , distribution and preferred orientation of trapped Y211 particles in solidified Y123 crystals depended on the growth direction and the growth rate as a function of undercooling. These phenomena could be at least qualitatively explained by the prevalent trapping/pushing theory considering the peritectic reaction as well as the faceted materials. In the Sm-system, a similar behavior of Sm211 particles was observed only in the Ba-enriched composition displaced from the Sm211-Sm123 tie-line. The results suggested that the variation of liquid composition altered the solid/liquid interfacial energy, which is one of the determining factors of particle pushing.
