Interactions between transitional impurities in noble (or transition) metal based alloys

Abstract

Using a hybridized tight binding and nearly free electron model for the host, the authors compute the density of states of isolated or pairs of transition atoms in noble or transition metals. For such pairs they calculate magnetic susceptibility, the specific heat and the low temperature dependent resistivity due to spin fluctuations in a simple RPA approximation. If one neglects for simplicity, Hund's coupling, the spin fluctuations of both impurities are characterized by two temperatures Tf+ and Tf- and each of the considered physical properties is expressed in terms of these temperatures. The change delta v of impurity potential in the presence of pair interactions is determined through Friedel's sum rule and is shown to be essential in all cases, especially in the asymptotic limit. The results of this numerical study of copper based alloys are in rather good agreement with the experimental data.