Resistance anomalies in the Kondo-lattice systemCeCu2−xNixSi2

The temperature-dependent resistance behavior of ${\mathrm{CeCu}}_{2\mathrm{-}\mathrm{x}}$ ${\mathrm{Ni}}_{\mathrm{x}}$ ${\mathrm{Si}}_2$ is consistent with the evolution of heavy fermions from strong mixed valence. The x dependence of the position of the resistance maximum ($T_m$) at low temperatures follows the same trend as that of the Kondo temperature ($T_K$). From this observation, we infer that $T_m$ is related to $T_K$. We also observe a direct correlation between the coefficient of $T^2$ (below 2 K) and the low-temperature susceptibility.