Magnetic properties of Fe-doped MnAl

Authors

• Priyanka Manchanda, University of Nebraska-LincolnFollow
• Arti Kashyap, LMN Institute of Information TechnologyFollow
• Jeffrey E. Shield, University of Nebraska-LincolnFollow
• L. H. Lewis, Northeastern UniversityFollow
• Ralph Skomski, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

4-2014

Citation

Published in Journal of Magnetism and Magnetic Materials 365 (2014), pp. 88–92; doi: 10.1016/j.jmmm.2014.04.007

Comments

Copyright © 2014 Elsevier B.V. Used by permission.

Abstract

Electronic and magnetic properties of L1₀-ordered Fe_xMn_1−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 μ_B per atom, as compared to the Mn moment, which exceeds 2.4 μ_B. 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 d_xy and d_zx minority density of states (DOS) at the Fermi level.