Indirect magnetic coupling between local moments in metals

Abstract

The coupling between pairs of localised magnetic moments in a nonmagnetic host metal is calculated using the generalisation of the Anderson model given by Caroli (1967), but without Caroli's restriction to asymptotically large ion-ion separations. Significant deviations from the asymptotic approximation are found when the two moments are within a few near-neighbour distances of each other. Comparisons are made with an independent calculation based on the same model and with the traditionally employed RKKY coupling derived from the s-d exchange model, and comments are made on the applicability of these calculations to dilute alloys (the so-called spin glasses) and to the magnetically concentrated Heusler alloys.