Eur. Phys. J. B (2025) 98: 211
https://doi.org/10.1140/epjb/s10051-025-01003-3

Regular Article - Solid State and Materials

Electronic structure and magnetic properties of the metastable ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloy films

Solid State Spectroscopy, G. V. Kurdyumov Institute for Metal Physics, N. A. S. of Ukraine, 36 Academician Vernadsky Boulevard, 03142, Kyiv, Ukraine

^a max_melnik@imp.kiev.ua

Received: 28 October 2024
Accepted: 17 July 2025
Published online: 10 October 2025

Abstract

A set of the metastable at room temperature (RT) ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloy films ($0.01\le \text{x}\le 0.98$) were fabricated using DC RT magnetron co-sputtering of Au and Fe targets. It was shown that the solid solution of Fe in face-centered cubic (FCC) Au is formed in ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloy films for $0.01\le \text{x}\le 0.77$. At $x\approx 0.80$, the transition from the FCC type to body-centered cubic (BCC)-type ordered ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloy films takes place. The first-principle calculations of the density of electronic states, the cohesive energies, and element resolved magnetic moments ($m_{\mathit{Au}}$ and $m_{\mathit{Fe}}$) have been performed for FCC-type ordered structures ${\text{L1}}_2$-${\text{Au}}_{0.75}{\text{Fe}}_{0.25}$, ${\text{L1}}_0$-${\text{Au}}_{0.50}{\text{Fe}}_{0.50}$, and ${\text{L1}}_2$-${\text{Au}}_{0.25}{\text{Fe}}_{0.75}$. The calculations reveal that among these alloys, the ${\text{Au}}_{0.25}{\text{Fe}}_{0.75}$ is the most stable as having the largest cohesive energy. It was also shown that both Au and Fe atoms contribute to the calculated resulting magnetic moment $M_{\mathit{AuFe}}$ of ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloys but have an opposite compositional dependence on Fe content. The general decrease in calculated magnetic moment of ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloys $M_{\mathit{AuFe}}$ with a decrease in x nicely agrees with the experimentally determined compositional dependence of magnetic properties of ${\text{Au}}_{1-x}{\text{Fe}}_x$ alloy films. Unlike the literature results, the experimentally determined M(x) dependence shows two different parts related to the films with FCC type or BCC type of structure.