Non-Fermi Liquid Behavior in Dilute Quadrupolar System Pr_xLa_1−xPb₃ with x≤0.05

Abstract

We have studied the low-temperature properties of Pr_xLa_1−xPb₃ with non-Kramers Γ₃ quadrupolar moments of the crystal-electric-field ground state, for a wide concentration range of Pr ions. For x≤0.05, the specific heat C⁄T increases monotonically below T=1.5 K, which can be scaled with a characteristic temperature T^* defined at each concentration x. The electrical resistivity ρ(T) in the corresponding temperature region shows a marked decrease deviating from a Fermi-liquid behavior ρ(T)∝T². The Kondo effect arising from the correlation between the dilute Γ₃ moments and the conduction electrons may give rise to such anomalous behavior.