Antiferromagnetic transitions in the Kondo lattice system ${\mathrm{Ce}}_2{\mathrm{Ni}}_3{\mathrm{Ge}}_5$

Our investigation of ${\mathrm{Ce}}_2{\mathrm{Ni}}_3{\mathrm{Ge}}_5$ by means of transport, specific heat and magnetization measurements shows that the compound is a Kondo lattice system exhibiting two antiferromagnetic transitions at $T_{N1\mathrm{}}=5.1\mathrm{}\mathrm{K}$ and $T_{N2\mathrm{}}=4.5\mathrm{}\mathrm{K}.$ An analysis of the transport and specific heat data suggests that the Kondo energy scale $k_B{T}_K$ is of the order of $k_B{T}_N.$ The resistivity and heat capacity data below 4 K are suggestive of the appearance of a spin-wave gap. The compound exhibits giant magnetoresistance at low temperature. The crystal field splitting is estimated to be about 180 K.