Degree of Order Dependence on Magnetocrystalline Anisotropy in Body-Centered Tetragonal FeCo Alloys

Abstract

We investigate the magnetocrystalline anisotropy (MCA) energy of tetragonal distorted FeCo alloys depending on the degree of order by first-principles electronic structure calculation combined with the coherent potential approximation. The obtained results indicate that the MCA energy of FeCo alloys strongly depends on the degree of order under optimal conditions, where the axial ratio of the bct structure is 1.25 and the composition is Fe 0.5 Co 0.5 . We find that the modification of the electronic structure resulting from electron scattering by chemical disorder has a considerable influence on the MCA under these conditions.

Effects of spin fluctuation on the magnetic anisotropy constant of itinerant electron magnets

“…In the present work, to confirm the above scenario, we calculate the MAE as a function of M for the tetragonally distorted (c/a = 1.2) FeCo disordered alloy [8,9], which was theoretically proposed by Burkert et al [8] to have large MAE. The FeCo disordered alloy is not a two-sublattice system, and it is completely different from the FePt system.…”

“…We selected MnAl because Al does not have strong SOI like Pt. Furthermore, as suggested by Kota et al, [9] the mechanisms of MAE occurrence for these systems differs. In this sense, the MnAl and FeCo alloys are adequate systems for investigating whether the model proposed by Mryasov et al is feasible.…”

“…[9] To obtain the MAE, the SOI is further required in the Hamiltonian, as demonstrated by Staunton et al [7] Although the inclusion of SOI requires considerable computer resources and time, this approach is unavoidable for realizing the direct dependence of M and K 1 on temperature. However, by concentrating only on the relationship between M (T ) and K 1 (T ), this expensive approach can be avoided by employing the disordered local moment (DLM) picture as follows.…”

High-Coercivity Fe-Co Nanoparticles Prepared by Pulsed Arc Plasma Deposition

“…First-principles calculations have shown that Fe-Co alloy can have a high uniaxial magnetocrystalline anisotropy (K u ) of up to 10 7 J·m ¹3 when its lattice is distorted into a bct crystal structure. 21,22) The crystal structure of Fe-Co nanoparticles deposited on SiO 2 nanoparticles was therefore investigated by TEM. A high-resolution TEM image is shown in Fig.…”

Investigation of magnetic anisotropy and magnetic moments of tetragonal distorted Fe1−xCox films on L1 FePt underlayer

“…[3][4][5] Based on the first-principle calculations, some groups predicted that tetragonal distorted FeCo alloy with a specific structure and alloy concentration resulted in a large uniaxial magnetic anisotropy. 6,7 On one hand, this distorted structure was expected to enhance the orbital magnetic moment by reducing the energy difference between d xy and d x 2…”