Critical resistivity of deviations from Matthiessen's rule of polyvalent metals

Abstract

Based on the isotropization mechanism of impurity scattering, the temperature dependence of the critical resistivity for the onset of deviations from Matthiessen's rule has been analyzed. It is shown that if a constant matrix element (for electron-phonon interaction) is used, the critical resistivity shows a T² dependence and that a T⁴ component also results if the momentum dependence of the matrix element is taken into account. At very low temperatures, where two orthogonalized-plane-wave corrections to the Fermi surface are important, the critical resistivity behaves as T³. It is shown that the experimental systematics of the critical resistivity can be understood within this framework.