Low-Temperature Properties in Dilute Quadrupolar Compound Pr_xLa_1−xInAg₂

Abstract

The low-temperature properties of Pr_xLa_1−xInAg₂ have been studied for a wide concentration range of Pr ions between 0≤x≤0.6. The susceptibility above T=15 K is well reproduced by the crystal-electric-field level scheme with a non-Kramers Γ₃ doublet in the ground state for each concentration, while that below T=15 K shows a non-Fermi-liquid behavior with a logarithmic temperature dependence. The temperature dependence of the specific heat C⁄T shows a monotonic enhancement below T=10 K, which can be scaled by a characteristic temperature T^* defined at each concentration. These results suggest that the anomalous low-temperature properties are understood as the single-ion nature of Γ₃ quadrupolar moments. The origin of the anomalous properties is discussed in connection with the quadrupolar Kondo effect arising from the correlation between the Γ₃ moments and the conduction electrons.