Magnetic and electrical properties of (Pu,Lu)Pd3

Abstract

We present measurements of the magnetic susceptibility, heat capacity and electrical resistivity of Pu$_{1-x}$Lu$_x$Pd$_3$, with $x$=0, 0.1, 0.2, 0.5, 0.8 and 1. PuPd$_3$ is an antiferromagnetic heavy fermion compound with $T_N=24$~K. With increasing Lu doping, both the Kondo and RKKY interaction strengths fall, as judged by the Sommerfeld coefficient $γ$ and Néel temperature $T_N$. Fits to a crystal field model of the resistivity also support these conclusions. The paramagnetic effective moment $μ_{\mathrm{eff}}$ increases with Lu dilution, indicating a decrease in the Kondo screening. In the highly dilute limit, $μ_{\mathrm{eff}}$ approaches the value predicted by intermediate coupling calculations. In conjunction with an observed Schottky peak at $\sim$60~K in the magnetic heat capacity, corresponding to a crystal field splitting of $\sim$12~meV, a mean-field intermediate coupling model with nearest neighbour interactions has been developed.

13 pages, 13 figures