Degree of order dependence on magnetocrystalline anisotropy in bct FeCo alloys

TL;DR

This study uses first-principles calculations to explore how the magnetocrystalline anisotropy energy in tetragonal FeCo alloys varies with the degree of atomic order, highlighting the impact of electronic structure modifications due to disorder.

Contribution

It provides new insights into the dependence of MCA energy on atomic order in FeCo alloys using combined electronic structure and CPA methods.

Findings

MCA energy strongly depends on the degree of order under optimal conditions.

Electronic structure modifications from chemical disorder significantly influence MCA.

Optimal tetragonal FeCo alloys have an axial ratio of 1.25 and composition Fe0.5Co0.5.

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 Fe0.5Co0.5. 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.