A model for compression dependence of thermal expansivity

In the present study, we propose a suitable model to compute volume dependence of thermal expansivity which is applicable up to infinite pressure or compression. The newly developed model satisfies the constraints of infinite pressure as suggested by high-pressure thermodynamics. The compression dependence of thermal expansivity for lower mantle of the Earth is evaluated with the help of the proposed model. A close agreement between theory and the results predicted with the seismic data is found, which in turn reveals the validity of the present work.