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

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.