PHONON-SCATTERING FROM DANGLING ELECTRONS AND DISLOCATIONS

The plastic deformations contribute to the thermal resistance in various phases, e.g. statically or dynamically. The role of phonon scattering towards heat transport due to the oscillating dislocations and due to the static strain-field and core dislocations has been studied for several alloy systems, namely, Ag-Cd, Ag-Pd, Cu-Zn, Cu-As and Au-Cr alloys for various concentrations of impurities. It has been reported that the dangling electrons present in the dislocation cores scatter phonons to offer sufficient thermal resistance to a solid in addition to the static dislocation scattering. Both type of (static and dynamic) scattering mechanisms are found to be equally effective approximately at the same frequency region (3 to 5 x 10(12) Hz) and hamper the other type of scatterings at low temperatures. The frequency values at which the strain-field and core dislocation collisions become equally effective have also been evaluated and found to be in good agreement with the relaxation rate spectrum.