Unusual Non-Fermi Liquid Behavior of Ce$_{1-x}$La$_{x}$Ni$_{9}$Ge$_4$   Analyzed in a Single Impurity Anderson Model with Crystal Field Effects
  CeNi$_{9}$Ge$_4$ exhibits unusual non-Fermi liquid behavior with the largest ever recorded value of the electronic specific heat $\Delta C/T \cong 5.5$ JK$^{-2}$mol$^{-1}$ without showing any evidence of magnetic order. Specific heat measurements show that the logarithmic increase of the Sommerfeld coefficient flattens off below 200 mK. In marked contrast, the local susceptibility $\Delta\chi$ levels off well above 200 mK and already becomes constant below 1 K. Furthermore, the entropy reaches 2$R$ln2 below 20 K corresponding to a four level system. An analysis of $C$ and $\chi$ was performed in terms of an $SU(N=4)$ single impurity Anderson model with additional crystal electric field (CEF) splitting. Numerical renormalization group calculations point to a possible consistent description of the different low temperature scales in $\Delta c$ and $\Delta \chi$ stemming from the interplay of Kondo effect and crystal field splitting. 
E.-W. Scheidt, F. Mayr, U. Killer, W. Scherer, H. Michor, E. Bauer, S.   Kehrein, Th. Pruschke, and F. Anders