The recently reported unusual behavior of the static and dynamical magnetic susceptibility as well as the specific heat in Ce1−xLaxNi9Ge4 has raised the question of a possible non-Fermi liquid ground state in this material. We argue that for a consistent physical picture the crystal field splitting of two low lying magnetic doublets of the Ce 4f-shell must be taken into account. Furthermore, we show that for a splitting of the order of the low temperature scale T∗ of the system a crossover behavior between an SU(4) and an SU(2) Kondo effect is found. The screening of the two doublets occurs on different temperature scales leading to a different behavior of the magnetic susceptibility and the specific heat at low temperatures. The experimentally accessible temperature regime down to 50mK still lies in the extended crossover regime into a strong coupling Fermi-liquid fixed point.
@article{arxiv.cond-mat/0511339,
title = {Can competition between crystal field and Kondo effect cause non-Fermi liquid like behavior?},
author = {Frithjof B. Anders and Thomas Pruschke},
journal= {arXiv preprint arXiv:cond-mat/0511339},
year = {2007}
}