THE PR-BA-CU-O AND ND-BA-CU-O SYSTEMS - PHASE-RELATIONSHIPS AT APPROXIMATELY 950-DEGREES-C

Systematic X-ray powder diffraction studies of the Nd2O3BaCO3CuO and PrOxBaCO3CuO systems at ∼950°C in air are presented as a function of cation molar ratios. In the pseudo-binary regions BaCuO2 was observed in both systems; Pr2CuO4 and BaPrO3, and Nd2CuO4 and BaNd2O4, were observed in the Pr and Nd systems, respectively. BaPr2O4 could be prepared only in a reducing atmosphere. In the pseudo-ternary regions the '123' and '336' phases were observed in the Pr system; the '123,' '336,' and '311' phases were observed in the Nd system. In the Pr system extensive solid-solution prevails between the '110,' '123,' and '336' phases and between the latter two phases and CuO. In the Nd system solid-solution was observed between '311,' '123,' and '336' phases, and between the latter two phases and CuO. © 1990.