# Surface Effects on the Magnetocrystalline Anisotropy of IrMn$_3$

## TL;DR

This study uses density functional calculations to analyze how surface terminations of IrMn₃ influence its magnetic anisotropy, which is crucial for understanding exchange bias in heterostructures.

## Contribution

It provides detailed computational insights into the surface-dependent magnetic anisotropy of IrMn₃ and its interface with Fe, highlighting the impact of different surface terminations.

## Key findings

- [111] surface exhibits perpendicular anisotropy of 1.62 meV/Ų
- [100] Ir-rich surface has in-plane anisotropy of 0.13 meV/Ų
- [100] Mn-rich surface has in-plane anisotropy of 1.39 meV/Ų

## Abstract

Magnetic anisotropy is a key parameter to describe the exchange bias effect in heterostructures. In this paper, we describe explicit density functional calculations of the magnetic structure of an interface between the industrially critically antiferromagnetic material, IrMn, and Fe, which together form a simple ferromagnet-antiferromagnet heterostructure. Additionally, the magnetic anisotropy was evaluated for several terminations of the IrMn. It was found that the [111] surface had a perpendicular anisotropy of 1.62 meV/$\text{\AA}^2$, whereas the two possible [100] surfaces (Ir-rich and Mn-rich) had in-plane anisotropies of 0.13 meV/$\text{\AA}^2$ and 1.39 meV/$\text{\AA}^2$ respectively. The affect of the magnetic order of the easy and hard configurations were calculated and used to explain the relative values of the anisotropies.