Further calculations of the energies of formation of Schottky defects in NaCl structure ionic crystals

The author presents the results of calculations of the energy of formation of Schottky defects in some alkali halides and alkaline earth oxides. It is shown that the basic Born-Mayer model of an ionic solid, which treats each ion as a point polarizable dipole, remains very adequate for defect energy calculations so long as the repulsive potential is chosen to give correctly the static dielectric constant of the substance it represents. The derived values for the alkali halides are in good agreement with experimental ones, particularly for those substances for which the latter are well documented, namely the potassium halides.