Anderson lattice in CeNiSi_2 intermediate valence compound
Abstract
We present experimental results of electrical resistivity, Hall coefficient, magnetic susceptibility, and specific heat for single crystals of Ce-based intervalent compound CeNiSi_2. The results show similar behaviors observed in Yb-based intervalent compounds and support recent thoery of the Anderson lattice, in which the Fermi-liquid coherence is gloval over the whole lattice. There is a low-temperature scale T_{coh} \sim 50 K for the onset of Fermi-liquid coherence, in addition to a high-temperature scale T_K^* \sim 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.