Magnetic and electrical properties of (Pu,Lu)Pd3

TL;DR

This study investigates how substituting Lu for Pu in PuPd3 affects its magnetic, electrical, and heat capacity properties, revealing a decrease in Kondo and RKKY interactions and changes in magnetic moments.

Contribution

It introduces a comprehensive analysis of (Pu,Lu)Pd3, combining experimental measurements with a mean-field intermediate coupling model to understand doping effects on magnetic interactions.

Findings

Both Kondo and RKKY interactions weaken with Lu doping.

The effective magnetic moment increases with Lu dilution.

A crystal field splitting of ~12 meV is identified.

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 $\gamma$ and N\'eel temperature $T_N$. Fits to a crystal field model of the resistivity also support these conclusions. The paramagnetic effective moment $\mu_{\mathrm{eff}}$ increases with Lu dilution, indicating a decrease in the Kondo screening. In the highly dilute limit, $\mu_{\mathrm{eff}}$ 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.