First-principles study of structural, magnetic and electronic properties of small FeRh alloy clusters

Abstract

The structural, electronic and magnetic properties of small ${\mathrm{Fe}}_m{\mathrm{Rh}}_n$ clusters having $N=m+n\le 8$ atoms are studied in the framework of a generalized-gradient approximation to density-functional theory. For $N=m+n\le 6$ a thorough sampling of all cluster topologies has been performed, while for $N=7$ and 8 only a few representative topologies are considered. In all cases the entire concentration range is systematically investigated. All the clusters show ferromagnetic-like order in the optimized structures. As a result, the average magnetic moment per atom ${\bar{\mu }}_N$ increases monotonously, which is almost linear over a wide range of concentration with Fe content. A remarkable enhancement of the local Fe moments beyond 3 ${\mu }_B$ is observed as result of Rh doping. The composition dependence of the binding energy, average magnetic moment and electronic structure are discussed.

17 pages, 4 figures, accepted in PRB