Electronic structure and magnetic anisotropies of antiferromagnetic transition-metal difluorides

TL;DR

This paper investigates the electronic structure and magnetic anisotropies of antiferromagnetic transition-metal difluorides using GGA+U calculations, revealing different origins of anisotropy and comparing theoretical predictions with experimental data.

Contribution

It provides a detailed analysis of magnetic anisotropies in MnF2, FeF2, CoF2, and NiF2, highlighting the dominant mechanisms and the dependence on band structure and U parameter.

Findings

MnF2 anisotropy mainly from dipolar interaction

Magnetocrystalline anisotropy dominates in FeF2, CoF2, NiF2

Theoretical predictions align closely with experiments for FeF2

Abstract

We compare GGA+U calculations with available experimental data and analyze the origin of magnetic anisotropies in MnF$_2$, FeF$_2$, CoF$_2$, and NiF$_2$. We confirm that the magnetic anisotropy of MnF$_2$ stems almost completely from the dipolar interaction, while magnetocrystalline anisotropy energy plays a dominant role in the other three compounds, and discuss how it depends on the details of band structure. The latter is critically compared to available optical measurements. The case of CoF$_2$, where magnetocrystalline anisotropy energy strongly depends on $U$, is put into contrast with FeF$_2$ where theoretical predictions of magnetic anisotropies are nearly quantitative.