On the Exact Origin of the lnTDependence of the Resistivity of Dilute Cd-Mn Alloys

The resistivity and susceptibility of dilute Cd. Mn alloys have been measured in the helium temperature range. Most of the previous existing data were taken on concentrated samples above the solid solubility limit and needed correction. The susceptibility follows a Curie-Weiss law with θ=0.1±0.05°K and p eff =(4.7±0.3)µ B , yielding a Kondo temperature of the order of 25m°K. Even on dilute samples, the impurity resistivity exhibits no deviation from a ln T dependence within the experimental accuracy. Such deviation from the Kondo ln T term is expected if one takes into account the most divergent higher order terms in perturbation theory. It is in fact shown that, even for high T / T K , a better understanding of the observed ln T dependence can be obtained for instance with Hamann's expression of the resistivity.