For applications of phase equilibria to the processing of second-generation high Tc superconductor-coated-conductors, phase diagrams constructed under carbonate-free conditions are needed. Subsolidus phase equilibria of BaO-R2O3-CuOz (R=Ho) have been investigated at pO2 = 100 Pa (810 C), 21 kPa (930 C), and 0.1 MPa (850 C and 930 C) by applying controlled atmosphere methods to minimize the presence of carbonate and CO2 and H2O contamination. Under carbonate-free conditions, most of these phase diagrams are different from those reported in the literature. In this paper, we also summarize and compare the phase diagrams of ten BaO-R2O3-CuOx systems (R=Nd, Sm, Eu, Gd, Dy, Y, Ho, Er, Tm and Yb) that were previously determined in this laboratory under pO2 = 100 Pa. Among these diagrams, a distinct trend of phase formation and tie-line relationships is observed.
Citation: Journal of Electronic Materials
Pub Type: Journals
(R=lanthanides and Y) systems, BaO-R2O3-CuOz, CO<sub>2</sub>-free conditions, coated conductors, phase diagrams