Phase equilibria in Y-Sr-Cu-O pseudoternary system at elevated oxygen pressure of 200 bar

We report the investigations on phase relations and phase compatibilities in Y-Sr-Cu-O pseudoternary at a temperature of 980degC and P(O2) = 200 bar. There is no evidence of a single phase quaternary compound. The SrO-CuO pseudobinary shows a remarkable difference as compared to its analog at 1 bar. Highly oxidized phases such as Sr2CuO3+δ and Sr14Cu24O41 are found to be stabilized under an oxidizing atmosphere of 200 bar. Sr14Cu24O41 has a solid solubility of Y for Sr up to a solubility limit of 30%. Partial melting is observed near the SrO vertex, where the presence of an unidentified quaternary peritectic is suggested by the appearance of additional XRD peaks. (orig.)