Empirical relationships between thermoelastic parameters

The knowledge gained recently from the thermodynamic constraints for materials at infinite pressure or extreme compression has been used in the present work to obtain empirical relationships between thermoelastic properties. The variations in thermal expansivity with the change in pressure are found to be related with the changes in the second-order Gruneisen parameter. This has been demonstrated by using the results based on the seismic data for the Earth lower mantle. It is also found that the variations in thermoelastic properties with pressure are represented well in terms of the bulk modulus and its pressure derivative based on the Stacey reciprocal K-primed equation of state. The melting temperatures for hcp iron at different pressures are found to be related with the Debye temperatures at the corresponding pressures.