The temperature dependence of FeRh's transport properties

TL;DR

This study uses first-principles calculations to analyze how the transport properties of FeRh change with temperature, especially around the metamagnetic transition, revealing the roles of electronic structure and magnetic disorder.

Contribution

It provides a detailed theoretical analysis of FeRh's temperature-dependent transport properties, linking electronic structure and magnetic disorder to resistivity changes.

Findings

Resistivity drops abruptly at the metamagnetic transition temperature.

Electronic structure differences at the Fermi level influence resistivity behavior.

Thermal magnetic disorder significantly affects transport properties.

Abstract

The finite-temperature transport properties of FeRh compounds are investigated by first-principles Density Functional Theory-based calculations. The focus is on the behavior of the longitudinal resistivity with rising temperature, which exhibits an abrupt decrease at the metamagnetic transition point, $T = T_m$ between ferro- and antiferromagnetic phases. A detailed electronic structure investigation for $T \geq 0$ K explains this feature and demonstrates the important role of (i) the difference of the electronic structure at the Fermi level between the two magnetically ordered states and (ii) the different degree of thermally induced magnetic disorder in the vicinity of $T_m$, giving different contributions to the resistivity. To support these conclusions, we also describe the temperature dependence of the spin-orbit induced anomalous Hall resistivity and Gilbert damping parameter. For the various response quantities considered the impact of thermal lattice vibrations and spin fluctuations on their temperature dependence is investigated in detail. Comparison with corresponding experimental data finds in general a very good agreement.