AB-INITIO CALCULATIONS OF THE DEVIATIONS FROM MATTHIESSEN RULE FOR DILUTE TERNARY ALLOYS

We report ab initio calculations of the residual resistivity and the deviations from Matthiessen's rule for dilute ternary alloys. We consider nonmagnetic (Cu) as well as ferromagnetic host materials (Ni) with an admixture of simple-metal (4sp, 5sp) or transition-metal (3d, 4d) impurities. The calculations are performed within the frame of density functional theory and the Korringa-Kohn-Rostoker Green's-function method. The transport is described quasiclassically by means of the Boltzmann equation. In the case of a ferromagnetic host a two-current model is applied. Both impurity atoms are considered as noninteracting and the scattering properties of each impurity atom are calculated self-consistently including in addition to the impurity potential one shell of perturbed host potentials around the impurity. Our results show satisfactory agreement with experiments and confirm the validity of Matthiessen's rule in nonmagnetic systems. In ferromagnetic systems the two-current model is confirmed.