Effect of Dislocations on the Thermal Conductivity of LiF

Phonon scattering by dislocations was studied by measuring the thermal conductivity of deformed LiF crystals from 1.5 to 300 K. The conductivity is not proportional to T 2 , as observed by Sproull et al. , but is approximately proportional to T 3.5 or to T 3 depending on the deformation mode. After annealing at 300°C for 10 min, the temperature dependence of the conductivity decreased. These results cannot be described in terms of the phonon scattering due to the static strain field around dislocations. The theory of phonon scattering by vibrating dislocations, advanced by Nabarro and Ninomiya, gives a consistent interpretation both to the temperature dependence and to the magnitude of the observed thermal conductivity.