Spatial decomposition of magnetic anisotropy in magnets: application for doped Fe16N2

TL;DR

This paper introduces a novel method to decompose magnetic anisotropy energy into atomic contributions using a relativistic energy variation approach, applied to doped Fe16N2 to identify enhancement mechanisms.

Contribution

The paper presents a new technique for spatially decomposing magnetic anisotropy energy in solids based on relativistic energy variation, applied to doped Fe16N2.

Findings

Pt doping increases MAE up to five times

Bi and Sb substitutions double the MAE

Spatial distribution of MAE enhancements demonstrated

Abstract

We propose a scheme of decomposition of the total relativistic energy in solids to intra- and interatomic contributions. The method is based on a variation of the speed of light from its value in relativistic theory to infinity (a non-relativistic limit). As an illustration of the method, we tested such decomposition in the case of a spin-orbit interaction variation for decomposition of the magnetic anisotropy energy (MAE) in CoPt. We further studied the {\alpha}''-Fe16N2 magnet doped by Bi, Sb, Co and Pt atoms. It has been found that the addition of Pt atoms can enhance the MAE by as large as five times while Bi and Sb substitutions double the total MAE. Using the proposed technique we demonstrate the spatial distribution of these enhancements. Our studies also suggest that Sb, Pt and Co substitutions could be synthesized by experiments.