Va. Konstantinov et al., ISOCHORIC THERMAL-CONDUCTIVITY OF SOLID F REONS OF METHANE SERIES - CF2CL2 AND CHF2CL, Fizika nizkih temperatur, 21(1), 1995, pp. 102-106
The isochoric thermal conductivity and the thermal pressure of solid f
reons of a methane series CF2Cl2 and CHF2Cl are studied near the melti
ng temperature. It is Found that the isochoric thermal conductivity of
CHF2Cl increases slowly with temperature whereas in the case of CF2Cl
2 it is practically constant. A correlation is made with another repre
sentatives of the methane series. The relation between the temperature
dependence of thermal conductivity and the nature of orientational mo
tion of ?he molecules is discussed. It is demonstrated that the behavi
or of thermal conductivity in orientationally-ordered phases fitted we
ll with the case of strong scattering and the concept of <<minimum>> t
hermal conductivity. The increase of the isochoric thermal conductivit
y in orientationally-disordered phases is accounted for by the decreas
e in phonon scattering by rotational excitations due to the weakening
of correlations in the rotation of neighboring molecules.