Thermodynamic treatment of coulomb interactions in non-stoichiometric oxides

Abstract

Due to the presence of charged defects, Coulomb interactions play a major role in a number of non-stoichiometric oxides. Various treatments of these interactions have been discussed. It has been shown that even for relatively high values of the dielectric constant, only two varieties of Monte-Carlo treatment, the Ewald summation method and minimum image with dodecahedron cells, provide reliable results. A typical consequence of these interactions is a strong increase of the partial molar enthalpy of oxygen near the stoichiometry due to the globally attractive nature of electrostatic interactions in dilute solutions.