Atomic Ordering in Fe2NiZ (Z = Al, Ga, In, Sn) Alloys: Effects on the Anisotropy and Properties of the Ground State

The effect of atomic configurations on the magnetic and structural properties of Fe2NiZ (Z = Al, Ga, In, Sn) Heusler alloys has been studied within the density functional theory. The competition between five structural motifs of the cubic phase due to permutations of Fe and Ni atoms is discussed. A new structure of the cubic phase with layer-by-layer atomic ordering of Fe and Ni atoms in the ground state is predicted. In this structural modification, the considered compounds have high magnetocrystalline anisotropy values that several times exceed the values for the FeNi alloy with tetragonal symmetry.