Single-grain growth, microstructure and superconducting properties of (Sm, Eu)123 superconductors with BaCuO2-x addition

High quality (SM0.5, Eu-0.5)Ba2Cu3O7-delta single domains were grown in air with BaCuO2-x addition. It was found that a RE-Ba substitution (RE: Sm and Eu) could be effectively suppressed by a small addition of BaCuO2-x. The 94 K superconductivity with sharp transition was obtained in the composition range of 0.16 similar to 0.33 BaCuO2-x and (Sm-0.5, Eu-0.5)Ba2Cu3O7-delta in a molar ratio. At 77 K, a surface field of 0.8 T was trapped in a single-domain pellet of 3.2 cm diameter. A further addition of BaCuO2-x deteriorated the microstructure and degraded the superconducting performance.