The effect of chemical disorder on the magnetic anisotropy of strained Fe-Co films

TL;DR

This study uses density-functional calculations to show that chemical order significantly enhances the magnetocrystalline anisotropy in strained Fe-Co films, providing insights for optimizing magnetic storage materials.

Contribution

It reveals the impact of chemical order on MCA and explores relaxation effects and strain energy to suggest optimal film preparation methods.

Findings

Chemical order greatly increases MCA in Fe-Co films.

Relaxation perpendicular to strain affects magnetic properties.

Strain energy varies with Co concentration and substrate lattice.

Abstract

Strained Fe-Co films have recently been demonstrated to exhibit a large magnetocrystalline anisotropy (MCA) and thus to be of potential interest as magnetic storage material. Here, we show by means of density-functional (DF) calculations, that chemical order can remarkably enhance the MCA. We also investigate the effect of relaxation perpendicular to the applied strain and evaluate the strain energy as a function of Co concentration and substrate lattice parameter. On this basis, favourable preparation routes for films with a large perpendicular anisotropy are suggested.