Defect interactions in alkali halides

Pairwise defect interactions between divalent cation impurities, cation vacancies and anion vacancies have been studied in the extrinsic and intrinsic temperature ranges for the KClSr2+ system. Pair correlation functions have been derived for the various defect interactions distinguished by their site symmetries and these show the existence of associated divalent cation—cation vacancy and cation—anion vacancy pairs even at high temperatures. Pair formation gives way to dissociation at low impurity concentrations and high temperatures.