CHEMICAL-POTENTIAL DIAGRAMS FOR RARE-EARTH TRANSITION-METAL OXYGEN SYSTEMS - I, LN-V-O AND LN-MN-O SYSTEMS

The thermodynamic properties of double oxides in rare earth‐transition metal (V and Mn)‐oxygen ternary systems have been collected and evaluated to examine their stability using chemical potential diagrams plotted as log (αA/αB) vs log (P(O2)). The thermodynamic regularities of perovskites, pyrochlores, and other compounds have been discussed in terms of the effective ionic radii across a series of rare earths. The obtained regularities have been used to estimate tentatively the thermodynamic properties of some rare‐earth vanadium and manganese oxides. Copyright © 1990, Wiley Blackwell. All rights reserved