Possible observation of quadrupolar Kondo effect in Pr-based dilute quadrupolar compounds

Abstract We have studied the low-temperature properties of Pr x La 1 - x Pb 3 and Pr x La 1 - x lnAg 2 with the crystal-electric-field (CEF) ground state of a non-Kramers Γ 3 doublet. In Pr x La 1 - x Pb 3 , non-Fermi-liquid (NFL) behavior has been observed for Pr concentrations x ≤ 0.05 in the specific heat C / T , susceptibility and electrical resistivity at low temperatures. Moreover, application of magnetic field raises C / T rapidly, which demonstrates the presence of the residual entropy at lower temperatures. In Pr x La 1 - x lnAg 2 , characteristic features have been seen up to x=0.8 in the susceptibility and specific heat below 15 K. These behaviors can be caused by the quadrupolar Kondo effect arising from the correlation between the dilute Γ 3 moments and the conduction electrons.