Phonon scattering by dislocations in metallic alloys

The theory of phonon scattering by fluttering dislocations of Ninomiya is applied to the thermal conductivity of copper alloys. Modifications made are the inclusion of a Peierls potential and of a restoring force on the dislocation due to solute atmospheres around the dislocation. In addition to the reradiation of phonons, scattering by the strain field around the dislocation and by the phonon-electron scattering are included to obtain the overall phonon relaxation rate. This theory is applied in particular to the lattice thermal conductivity of copper-aluminum alloys. The effects of dispersal of the atmospheres by moderate annealing is discussed. Agreement with experiment in the vicinity of the "bow" around 2-3 K could be obtained.