Magnetic properties of Fe-doped MnAl

• Magnetic properties of L10-ordered FexMn1−xAl alloys are investigated.
• DFT predicts the enhancement in magnetic anisotropy with Fe content.
• The magnetic moment decreases with Fe concentration in MnAl.

Electronic and magnetic properties of L10-ordered FexMn1−xAl alloys (x=0, 0.0625, 0.125, 0.1875, 0.5) are investigated by first-principle supercell calculations. Pristine MnAl exhibits robust ferromagnetism involving the dense-packed Mn atoms in (001) planes of the tetragonal structure. Iron substitution for Mn significantly deteriorates the magnetization of the alloy. The reduction is a dilution effect, caused by the relatively small Fe moment of about 1.9 μB per atom, as compared to the Mn moment, which exceeds 2.4 μB. By contrast, 50% Fe substituted for Mn (x=0.5) yields a magnetocrystalline anisotropy enhancement of about 40%. Both the magnetization reduction and the anisotropy enhancement mainly arise due to the change in dxy and dzx minority density of states (DOS) at the Fermi level.