SMBA2CU3O6.5 SEED FABRICATION FOR SEEDED PERITECTIC SOLIDIFICATION OFYBA2CU3O7-DELTA

The availability of high quality SmBa2Cu3O6.5 seeds of known orientati on is essential for the fabrication of a large grain YBa2Cu3O7-delta ( YBCO) superconductor via a seeded peritectic solidification technique. The suitable seed must have a close lattice parameter match to YBCO a nd a relatively high melting temperature. We report a melt texturing p rocess for the fabrication of SmBa2Cu3O7-delta (Sm-123) seeds using Sr TiO3 to control grain nucleation. The physical and structural properti es of the seeds were confirmed by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Seeds prepared in this study were used to grow large single grain YBCO supe rconductors of up to 2 cm in diameter.