HIGH-TEMPERATURE PHASE RELATIONSHIP IN THE PRBAO3-BACU3O4 QUASI-BINARY SYSTEM

Further development of the process to synthesize Pr1Ba2Cu3O7-delta (Pr123) single crystals is desirable for future applications of high temperature superconductive oxides. However, the phase diagram of the Pr123 oxide, in particular in the temperature range of melting and decomposition, has not been fully investigated. In this work, the peritectic temperature of Pr123 was measured by differential thermal analysis (DTA) and by X-ray diffraction (XRD) after appropriate quenching experiments. The stable phases were identified by XRD for the same quenching experiments. Furthermore, the solubility of Pr in the BaCu3O4 melt was measured. As a result, the PrBaO3 (Pr110) phase was confirmed to be the higher temperature stable phase. Expressions for the liquidus lines, the enthalpy of dissolution of Pr and the slopes of the liquidus lines at the peritectic temperature of Pr123 were obtained for the different stable phases (Pr110 and Pr123).