Magnetic, transport, and thermal properties of $\delta$-phase UZr$_2$

TL;DR

This study comprehensively investigates the magnetic, transport, and thermal properties of $$-phase UZr$_2$ alloys through experimental measurements and theoretical calculations, revealing insights into electron behavior and disorder.

Contribution

First detailed experimental and theoretical analysis of $$-phase UZr$_2$ properties across a wide temperature and magnetic field range.

Findings

Weak temperature dependence of magnetic susceptibility

Small Seebeck coefficient indicating delocalized 5f-electrons

Presence of significant electronic disorder

Abstract

Alloys of hexagonal $\delta$-phase UZr$_2$ have been synthesized and studied by means of heat capacity, magnetic susceptibility, magnetization, electrical resistivity, magnetoresistance, thermoelectric power, thermal conductivity measurements, for the first time, at temperatures from 1.8 to 300 K and in magnetic fields up to 8 T. The weak temperature dependence of the magnetic susceptibility and the small value of both Seebeck (0.75 $\mu$V/K at room temperature) and of the Sommerfeld coefficient (13.5 mJ mol$^{-1}$ K$^{-2}$) point to 5$f$-electrons in this material having a delocalized nature. The electrical resistivity and magnetoresistance indicate the presence of significant electronic disorder in $\delta$-UZr$_2$, consistent with the disorder in its crystal structure. Density functional theory calculations have been performed and compared to experimental results.