Microscopic Study of Intermediate Valence of Extremely Dilute Ce Ions in Thorium

Abstract

The static and dynamic magnetic response of isolated Ce ions in Th metal is microscopically observed by the time-differential perturbed $\ensuremath{\gamma}$-ray distribution method. The single---Ce-ion behavior reflects intermediate valence and a temperature-driven transition from nonmagnetic to magnetic in the range 18 to 800 K.