Development of a magnetic interatomic potential for cubic anti-ferromagnets: the case of NiO

TL;DR

This paper introduces a new methodology to incorporate magnetic properties into interatomic potentials for cubic antiferromagnets, demonstrated on NiO, enabling advanced large-scale simulations of magnetoelastic phenomena.

Contribution

The authors develop a novel approach to embed magnetic interactions into interatomic potentials for cubic antiferromagnets, validated on NiO with two different potential models.

Findings

Potential models accurately reproduce DFT-calculated properties

Magnetoelastic interactions are effectively incorporated

Models enable large-scale magnetoelastic simulations

Abstract

Interatomic potentials are essential for molecular dynamics simulations of magnetic materials, yet incorporating magnetic features into potentials for complex antiferromagnets remains challenging. Nickel oxide (NiO), a prototypical cubic antiferromagnet, exemplifies this difficulty. Here we develop a methodology to integrate magnetic properties into interatomic potentials for cubic antiferromagnets by adding a magnetic Hamiltonian which includes both the Heisenberg exchange and N\'eel model. We apply this approach to NiO by constructing two potentials: one based on the Born model of ionic solids and another using a reference-free modified embedded atom method. Both potentials include magnetoelastic interactions and are validated against Density Functional Theory calculations, showing excellent agreement in mechanical and magnetic properties at zero temperature. These models enable large-scale simulations of magnetoelastic phenomena in antiferromagnets and open avenues for molecular dynamics studies involving coupled electric and magnetic fields in metal oxides.