The thermal conductivity jump at crystal-liquid phase transition in CHCl₃, C₆H₆, and CCl₄: the action of rotational molecular motion

Abstract

The thermal conductivity of liquid CHCl₃, C₆H₆, and CCl₄ was measured by steady-state method under saturated vapour pressure in the temperature areas that correspond to pre-crystallization temperatures. Based on the obtained experimental results, we have investigated the isobaric thermal conductivity jump ΔΛp at crystal–liquid phase transition in CHCl₃, C₆H₆, and CCl₄. The contributions of the phonon–phonon and phonon–rotational interaction to the total thermal resistance, in solid and liquid state, are specified using modified method of reduced coordinates. A reduction in the thermal conductivity ΔΛp at crystal–liquid phase transition is explained by a combined effect of variations in positional distribution of molecules and in form of rotational molecular motion.