Exchange reactions of oxides. Part X. The rare-earth sesquioxides

Abstract

The kinetics of exchange of oxygen-18 between enriched oxygen gas and the stable rare-earth sesquioxides, and of terbium oxide, have been examined. Most of the oxides exchange by a dissociative mechanism confined to the surface layer of oxygen ions. As for other metallic oxides there is a strong compensation effect between A₀ and E in the rate expression and there is as before a correlation between the size of the unit cell and related crystal parameters and E. There is no correlation between magnetic properties of the M³⁺ ion and the exchange kinetics.