Abstract
An expression is obtained for the lattice thermal conductivity at high temperatures in the limit when the scattering of phonons by point defects is stronger than by umklapp processes. The latter limit the phonon mean free path at low frequencies and most of the heat is transported at frequencies such that the point defect and umklapp mean free paths are equal. The conductivity varies as , where is proportional to the strength of the point defect scattering, is the temperature. The theory is in rough agreement with the thermal conductivity of Ge-Si alloys, measured by Steele and Rosi.
- Received 7 March 1960
DOI:https://doi.org/10.1103/PhysRev.119.507
©1960 American Physical Society