Simulation of defects formed by cations of bivalent and trivalent metals in the structure of potassium dihydrogen phosphate: A computational technique

Abstract

This paper reports on the results of crystal chemical analysis and computer simulation of the defect structure of potassium dihydrogen phosphate (KDP) containing impurities of bivalent and trivalent metals. It is shown that these impurities can form defect centers of different types: isolated centers formed by M ³⁺ and Ni²⁺ ions and, in part, by Co²⁺ ions at interstitial sites, chains composed of M ²⁺ impurity ions with radii from ≈0.65 to ≈1.1 Å, and centers created through the substitution of large-sized bivalent cations for potassium ions either with the formation of additional potassium vacancies or through the heterovalent isomorphism mechanism. The calculations are performed using different-type interatomic interaction potentials, and a comparative analysis of the results obtained is carried out.