Non-Fermi Liquid Behavior in Dilute Quadrupolar System Pr${}_x$La${}_{1-x}$Pb${}_3$ with $x$$\le$0.05

Abstract

We have studied the low-temperature properties of Pr${}_x$La${}_{1-x}$Pb${}_3$ with non-Kramers ${\Gamma }_3$ quadrupolar moments of the crystal-electric-field ground state, for a wide concentration range of Pr ions. For $x$$\le$0.05, the specific heat $C/T$ increases monotonically below $T$=1.5 K, which can be scaled with a characteristic temperature $T^{\ast }$ defined at each concentration $x$. The electrical resistivity $\rho$$(T)$ in the corresponding temperature region shows a marked decrease deviating from a Fermi-liquid behavior $\rho$$(T)$$\propto$$T^2$. The Kondo effect arising from the correlation between the dilute ${\Gamma }_3$ moments and the conduction electrons may give rise to such anomalous behavior.