Diffusion in stoichiometric and non-stoichiometric cubic oxides

Abstract

From diffusion measurements in readily classified “stoichiometric” or “non-stoichiometric” cubic oxides we have deduced formation and migration enthalpies of point defects.

Such information cannot be deduced in the case of large departures from stoichiometry as point defects are strongly interacting. In the case of oxides with small departures from stoichiometry, “chemical self-diffusion” experiments give direct information on the migration of the species responsible for the non-stoichiometry.

Systematic studies of the diffusion of series of homovalent impurities are a convenient way to find some general trends of the diffusion parameters and to rely them to physical properties of the impurities and of the host crystal, in stoichiometric or in non-stoichiometric oxides as well.