Impact of iron composition on the calculated electronic and magnetic properties of Fe3−xNixSi

Abstract

ABSTRACTThe structural, electronic and magnetic properties of Fe3−xNixSi alloys with variable iron composition (0 ≤ x ≤ 1) have been investigated within by using Projector augmented wave (PAW) method. The exchange–correlation potential was treated with the generalised gradient approximation (GGA) for the calculation of the structural properties and for the computation of the electronic and magnetic properties in order to treat the d states. These alloys crystallize in cubic Heusler structures; The Fe3Si and Fe2NiSi have a regular structure DO3 and L21 respectively. To describe the experimental proprieties we use the on-site Coulomb interactions of Ueff(Ni) = 3.1 eV and Ueff(Fe) = 3.4 eV. A good agreement between calculated and experimental magnetic moments is found for the cubic Heusler phases without the addition of Hubbard-model. The obtained results of the density of states and the spin-polarized band structure show that the Fe2NiSi alloy has half-metallic property. Through the obtained values of the total spin magnetic moment, we conclude that in general, the Fe2NiSi alloy is half-metallic ferromagnet material whereas the Fe3Si alloy has a metallic nature.