Interaction between thermal phonons and dislocations in LiF

Abstract

All measurements of thermal conductivity and ballistic phonon propagation in crystals of deformed LiF over the temperature range 0.03-25K are consistent with an interpretation in which the slow transverse phonons are scattered with much greater probability by dislocations than are fast transverse phonons. The scattering is too strong to be explained by static mechanisms of phonon-dislocation interaction, but is in rough agreement with a vibration-string mechanism. The present string model does not, however, provide the quantitative details observed experimentally.