Thermal behavior of compressed materials

Differences in volumes of materials compressed by the static (cold) and shock-wave (adiabatic) methods are caused by the enhanced temperatures in the last case. Using experimental data for compressed materials we determined coefficients of thermal expansion under pressures for 49 elements, most of which demonstrate the positive sign, but Rb, Sr, Ga, Sb, Cgra and I under 1 GPa; Ti, V, Re, I, Fe, Ir and Th under 10 GPa show negative coefficients of thermal expansion. In the case of Th, La, Ga, Zr, Sn, Sb and Ir a sign of the volume change depends on the pressure values.