CALCULATION OF SUBSOLIDUS PHASE RELATION DIAGRAMS OF Y-Ba-Cu-O SYSTEM
(Central South University of Technology, Changsha 410083, China)
Abstract: Mathematical principle and method for the calculation of subsolidus phase relation diagrams of the quasi-ternary system YO1.5-BaO-CuO were developed, and the corresponding mathematical model was established. Subsolidus phase relation diagrams of this system at different temperatures were calculated from thermodynamic data. The calculated results showed that in Y-Ba-Cu-O system BaCuO2 and Y2BaCuO5 are thermodynamically stable at room-temperature, and Y2Cu2O5 and YBa2Cu3O6.5 also become stable at temperatures higher than 300 ℃ and 750 ℃ respectively. The calculated results are in good agreement with those from experiments.
Key words: superconductor, yttrium-barium-copper-oxygen system, phase diagrams