A simple technique for the preparation of R.E. FeO3 and R.E. CoO3

Abstract

Rare earth orthoferrites and the analogous cobalt compounds can be prepared by the thermal decomposition of the appropriate rare earth ferricyanide or cobalticyanide compound, e.g., LaFe(CN)6·XH2O. These compounds are readily precipitated from aqueous solution and since the excess of either component remains in solution there is precise control of stoichiometry. Similarly, the ferrocyanide compounds, NH4 R.E. Fe(CN)6·XH2O may be utilized. Because the mixing is on an atomic scale, the desired compound is achieved by a single relatively low temperature calcination and without any subsequent milling or contamination.