Crystal field and Kondo effects in CeCu6 and CeAl3.

Abstract

We calculate the temperature dependence of the specific heat, susceptibility, and resistivity for an isolated cerium ion in crystal-field environments appropriate for the cerium sites in ${\mathrm{CeCu}}_{6}$ and ${\mathrm{CeAl}}_{3}$. We use the self-consistent ladder approximation for intermediate and high temperatures and match to exact results to obtain low-temperature behavior. We find unusual temperature dependence for all the calculated quantities as a result of the competition between crystal-field effects and the Kondo effect. Our results for specific heat and susceptibility agree well with the data, except that the independent ion approximation predicts somewhat smaller Wilson ratios than observed, perhaps implying weak ferromagnetic correlations. The resistivity is not well reproduced.