Possible Low-Temperature Strongly Correlated Electron Behavior from Multipole Fluctuations in PrMg3 with Cubic Non-Kramers Γ3 Doublet Ground State

Abstract

The magnetic and thermodynamic properties of PrMg 3 single crystals were investigated based on the magnetic susceptibility χ( T ) and the specific heat C P ( T ). An observed broad anomaly in C P ( T ) with a peak ∼1.8 J/(mol K) at 0.9 K, together with Van-Vleck-like behavior of χ( T ), indicates that the low- T properties are ascribed to the multipole (quadrupole O 20 and O 22 , and octupole T x y z ) degrees of freedom of a nonmagnetic, non-Kramers Γ 3 doublet ground state in the cubic crystalline electric field of Pr 3+ . The low- T C P ( T ) anomaly, however, is not described in terms of the two-channel Kondo model, but is more similar to that for the single-channel Kondo model with the Kondo temperature T K = 1.3 K, including its weak external-field dependence. No evidence for a cooperative phase transition was detected down to 0.54 K in C P ( T ), suggesting that the Γ 3 multipole degrees of freedom are quenched at low T by forming a strongly correlated electronic state through the hybridization wit...