Enhancing electronic, magnetic, and elastic properties of SmFe2 by Mn substitution at Fe sites: A first-principle computational study

Abstract

In this comprehensive theoretical investigation, we present the effects of manganese (Mn) substitution for iron (Fe) in samarium iron (SmFe2) on its electronic, magnetic, elastic, and magnetostriction properties, utilizing state-of-the-art Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA) complemented by the Full Potential Linearized Augmented Plane Wave (FP-LAPW) method. Our investigations are further enriched by Monte Carlo simulations framed within the Ising model, providing a comprehensive understanding of the material's behavior under Mn doping. Our findings reveal a significant shift in magnetic anisotropy from the [100] direction in pristine SmFe2 to the [111] direction following Mn substitution. This transition enhances the material's magnetic favorability and introduces new electronic states at the Fermi level, increasing the number of states available for conduction and enhancing its metallic behavior. Consequently, this transition results in altered elastic constants and magnetostriction values, highlighting a delicate interplay between the material's structural and magnetic properties that warrants further exploration. By developing a Hamiltonian model, we delve into the intricate coupling among magnetic atoms within SmFe2, offering insights into the underlying mechanisms governing the observed phenomena. Monte Carlo simulations further corroborate the robust ferromagnetic ordering of SmFe2, evidenced by a high critical temperature (Tc = 651.3 K).