Surface nucleation, domain growth mechanisms, and factors dominating superconducting properties in seeded melt grown YBa₂Cu₃O_x

Using a seeded melt growth (SMG) method, we have produced single-domain YBa₂Cu₃O_x with high levitation forces and trapped magnetic fields. A threshold temperature T_L has been found above which extraneous nucleation does not occur. Surface nucleation has been suppressed when the top sample surface is coated with low melting compounds. The planar growth rates along the a- and c-axes have been found to be comparable within the undercooling range used in this study, and agree well with the current model. Major factors that strongly influence the levitation force have been studied in detail including domain geometry and orientation. Current physical models have been used to interpret the observed levitation force behaviors.