Formation of the YBa2Cu3O7-δ-phase during melt processing

Abstract The crystallization behavior of YBa 2 Cu 3 O 7-δ (123) with additives of Y 2 BaCuO 5 (211), Ag 2 O and PtO 2 was studied by microstructure analysis of samples quenched at intermediate stages of the melt process. The samples were investigated by STEM, XRD and DTA. The peritectic growth of 123 is found to be accomplished by dissolution of 211 in the liquid close to the 123 growth front and reprecipitation of its constituents at the growing interface. A large undercooling is observed being probably due to the presence of solved Ag in the liquid.