Infrared Absorption Spectra of Solid Solutions: Cluster Formation of Nitrate Ions in Alkali Halides

Abstract

Satellite bands appearing in spectra of dilute solid solutions of nitrate ions in alkali halide crystals have been identified as arising from clusters of two or more nitrate ions. The dependence of the number of clusters on the concentration has been determined. Out of the discrepancy between this dependence and the theoretically expected dependence an interaction energy can be estimated.