Thermal conductivity and heat capacity of single-crystal LiF and CaF₂ under hydrostatic pressure

The thermal conductivity, lambda , and heat capacity per unit volume, rho c_p, have been measured under hydrostatic pressure up to 1 GPa at room temperature, using a dynamic two-strip method. The standard deviation of lambda and rho c_p was always better than 0.2%. The volume dependence of lambda expressed in terms of the Bridgman parameter, -( delta ln lambda / delta ln V)_T, was found to be 7.9 for LiF and 9.2 for CaF₂. The specific heat capacity, c_p, calculated from the measured rho c_p, was found to decrease slightly with increasing pressure.