Multi-seeded melt crystallization of YBCO bulk material for cryogenic applications

Abstract

YBCO bulk materials were crystallized by a multi-seeded melt growth process. Up to four biaxial oriented Sm-123 seeds were placed on the top of rectangular shaped YBCO bars (up to ). The oriented grown single grains are joined by partially coherent grain boundaries with an improved current transport capability and high levitation forces with overall values of 55-65 N. Segregation of nonsuperconducting rest melt and microcracks limit the current transport across the grain boundary.