First-Principles Calculations of the Structural, Magnetic, and Electronic Properties of $$\hbox {Fe}_{2}\hbox {MgB}$$ Full-Heusler Alloy

Abstract

The structural, magnetic, and electronic properties of a new $$\hbox {Fe}_{2}\hbox {MgB}$$ full-Heusler alloy were calculated using a first-principles approach based on density functional theory. The conventional $$\hbox {Cu}_{2}\hbox {MnAl}$$ -type and inverse $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type structures in nonmagnetic and ferromagnetic states were considered for the full-Heusler alloy. The ferromagnetic $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type structure was found to be the most energetically favourable. $$\hbox {Fe}_{2}\hbox {MgB}$$ with ferromagnetic structure has a molecular magnetic moment of 3.000 $$\mu _{B}$$ at the equilibrium lattice constant of 5.562 A. The molecular magnetic moment originates from the alloy’s two Fe atoms and obeys the Slater–Pauling rule. The majority-spin channels are metallic, whereas the minority-spin electrons exhibited a semiconducting behaviour with an indirect narrow gap of 0.179 eV in the equilibrium state. The ferromagnetic $$\hbox {Hg}_{2}\hbox {CuTi}$$ -type $$\hbox {Fe}_{2}\hbox {MgB}$$ is proven to be a potential half-metallic material suitable for use in spintronics.