Heavy-fermion behavior and the single-ion Kondo model

Abstract

Measurements of the temperature and concentration dependence of the specific heat, magnetic susceptibility, and electrical resistivity for ${\mathrm{Ce}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{La}}_{\mathrm{x}}$${\mathrm{Pb}}_{3}$ are presented. The data scale with the concentration of Ce ions over surprisingly large intervals of x and T. The low-temperature specific heat per Ce ion agrees quantitatively with that of an S=(1/2) Kondo impurity of ${T}_{K}$apeq23.3 K. These results strongly suggest that intersite correlations do not play the expected important role and that the high specific heat \ensuremath{\gamma} reported for ${\mathrm{CePb}}_{3}$ is mainly a manifestation of the single-ion Kondo resonance.