Deviations from Matthiessen's rule in K and Li: A comparison with other metals

Abstract

The existing experimental data are evaluated on the temperature-dependent electrical resistivity of K and Li samples of varying degees of purity. The rate at which deviations from Matthiessen's rule (DMR) are induced with increasing impurity scattering is derived. It is found that this rate is comparable with that observed in other metals with varying degrees of anisotropy, either in Fermi surface or in Umklapp to normal scattering ratio. This similarity of behavior is more evident if normalized temperature and resistivity scales are used. This finding is in disagreement with the predictions of the theoretical models, which attribute DMR to the isotropization of the distribution function due to impurity scattering.