A Study of Bonding and other Related Properties of Some Rutile type Oxide Crystals.

Abstract

A theoretical analysis of the interionic potential in four rutile-type oxide crystals has been made within the framework of ionic model using eight repulsive interactions including one proposed in this work. The sui tabi 1 i ty of the new £-nteraetion, potentia 1 as applied to these system is discussed. A new complete set of polarizability values of the ions concerned has also been derived. The lattice energy and pressure derivative of bulk moduli are evaluated for the entire family of crystals under study. The resulting values are compared with the available ex~erimental data and other recent theoretical calculations. We have also considered the question of the degree of ,ionicity of the compounds under study as there seems to be some controversy regarding these in literature.The present study indicates that the bonding in rutile although some covalent contri is predominantly ionic, bution is present.