Influence of Interactions Between Impurities on the Appearance of Magnetic Moments in Copper-Cobalt Dilute Alloys

Abstract

A simple model is used to describe the magnetic properties of cobalt impurities in copper. Isolated impurities are nonmagnetic with a high spin-fluctuation temperature. Isolated pairs of neighbor cobalt atoms are very nearly magnetic: This gives rise to a large susceptibility and a large electronic specific heat, varying as the square of the concentration $C$. At low temperatures, only the group of three (or more) cobalt atoms carries a magnetic moment.