The thermal conductivity of solid SF 6 , CHCI 3 , C 6 H 6 , and CCl 4 was investigated by the linear-flow method under saturated vapor pressures in the temperature range from 80 K to the corresponding melting temperatures and then recalculated for a constant density of the samples. The contributions of the phonon-phonon and phonon-rotation interactions to the total thermal resistance were separated using the modified method of reduced coordinates. It is shown that the phonon-rotation contribution to the thermal resistance of the crystals decreases as the rotational motion of the molecules attains more freedom.

The isobaric thermal conductivity of solid SF6 is investigated in the high-temperature phase. The experimental results are rescaled to a constant density. The isochoric thermal conductivity initially decreases with increasing temperature, then passes through a smooth minimum and begins to grow. A modified version of the reduced coordinate method is used to calculate the phonon–phonon and phonon–rotational contributions to the total thermal resistance. The growth of the isochoric thermal conductivity is explained by a weakening of the scattering of phonons on collective rotational excitations of the molecules as the correlations of the rotation weaken.

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