TEMPERATURE AND PRESSURE DEPENDENCE OF ELASTIC PROPERTIES OF EARTH’S LOWER MANTLE COMPONENTS

Abstract

The expressions for the temperature and pressure derivatives of Second Order Elastic (SOE) constants of elements of earth’s lower mantle i.e. CaO, MgO and SrO have been obtained using a simple method of direct differentiation of expressions of SOE constants which have been suitably modified taking into account three body interaction and thermal phonon pressure. The method provides a direct check to the already known expressions of pressure derivatives of SOE constants using Thurston and Brugger relation. The results obtained at 300° K are found to be in reasonably good agreement with the experiment.