Electronic structure and magnetic properties in T2AlB2 (T = Fe, Mn, Cr, Co, and Ni) and their alloys
Abstract
Fe2AlB2 is one of the promising candidates for magnetic refrigeration technology and has attracted great attention since the recent discovery of its substantial magnetocaloric effect around room temperature. The electronic structure and intrinsic magnetic properties of Fe2AlB2-related compounds and their alloys have been investigated using density functional theory. For Fe2AlB2, the crystallographic a axis is the easy axis, in agreement with experiment. The magnetic ground state of Mn2AlB2 is found to be ferromagnetic in the basal ab plane, but antiferromagnetic along the c axis. All 3d dopants considered decrease the magnetization and Curie temperature in Fe2AlB2. Electron doping with Co or Ni has a stronger effect on the decreasing of Curie temperature in Fe2AlB2 than hole doping with Mn or Cr. However, a larger amount of Mn doping in Fe2AlB2 promotes a ferromagnetic to antiferromagnetic transition. A very anisotropic magnetoelastic effect is found in Fe2AlB2: the magnetization has a much stronger dependence on the lattice parameter c than on a or b, which is explained by electronic-structure features near the Fermi level.
This work was supported by the U.S. Department of Energy, Advanced Research Projects Agency-Energy (ARPA-E) under Grant No. 1002-2147.- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARB41012H