Anderson lattice in CeNiSi₂ intermediate valence compound

We present experimental results of electrical resistivity, Hall coefficient, magnetic susceptibility, and specific heat for single crystals of the Ce-based intervalent compound CeNiSi₂. The results show similar behaviors observed in Yb-based intervalent compounds and support a recent theory of the Anderson lattice, in which the Fermi-liquid coherence is gloval over the whole lattice. There is a low-temperature scale T_coh∼50 K for the onset of Fermi-liquid coherence, in addition to a high-temperature scale T*_K∼150 K for the Kondo lattice condensation. Therefore we conclude that two energy scales are generic in intermediate valence compounds based on Ce where the orbital degeneracy is smaller and where the size of the 4f orbital is larger than those based on Yb.