Thermodynamic analysis of elastic modulus temperature dependence of nonmagnetic metals under all-round pressure

A thermodynamic approach to the calculation of elastic modulus in nonmagnetic metals under all-round compression is developed. The main contribution to the temperature dependence of elastic modulus falls on the contribution from thermal acoustic phonons to for energy. Within the range of low and high temperatures (in comparison with Debye temperature) the contribution in question is proportional to the energy of thermal acoustic phonons, however, the coefficients of proportionality between the elastic modulus and the crystal energy are different in this two limiting cases. This manifests itself in the appearance of a bend in the temperature dependence of elastic modulus. The analysis of elastic modulus of paramagnetic lutetium under conditions of all-round compression is accomplished to show an agreement of the approach developed with the experimental data