Superconductivity and Normal-State Properties of ThU Alloys

Anomalies in the normal-state electrical resistivity, thermoelectric power, and magnetic susceptibility have been observed in dilute alloys of uranium dissolved in thorium. These anomalies appear to be due to localized spin fluctuations with a characteristic temperature T-0 similar to 100K which are associated with 5f virtual bound states on the U atoms. The depression of the superconducting transition temperature of Th by U impurities is large and deviates markedly from the form given by the Abrikosov-Gor'kov theory.