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

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ΔΛp at the 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 a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ΔΛp, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.