Thermodynamical and topological properties of metastable Fe3Sn

TL;DR

This study combines experimental data, first-principles calculations, and thermodynamic assessments to analyze the thermodynamic and topological transport properties of the metastable Fe3Sn phase, revealing tunable anomalous conductivities.

Contribution

It introduces the metastable Fe3Sn phase into the phase diagram and investigates its topological transport properties with doping and magnetization adjustments.

Findings

Fe3Sn phase incorporated into phase diagram.

Enhanced anomalous Hall and Nernst conductivities observed.

Transport properties tunable via doping and magnetization direction.

Abstract

Combining experimental data, first-principles calculations, and Calphad assessment, thermodynamic and topological transport properties of the Fe-Sn system were investigated. Density functional theory (DFT) calculations were performed to evaluate the intermetallics' finite-temperature heat capacity (Cp). A consistent thermodynamic assessment of the Fe-Sn phase diagram was achieved by using the experimental and DFT results, together with all available data from previous publications. Hence, the metastable phase Fe3Sn was firstly introduced into the current metastable phase diagram, and corrected phase locations of Fe5Sn3 and Fe3Sn2 under the newly measured corrected temperature ranges. Furthermore, the anomalous Hall conductivity and anomalous Nernst conductivity of Fe3Sn were calculated, with magnetization directions and doping considered as perturbations to tune such transport properties. It was observed that the enhanced anomalous Hall and Nernst conductivities originate from the combination of nodal lines and small gap areas that can be tuned by doping Mn at Fe sites and varying magnetization direction