Strain-induced Shape Anisotropy in Antiferromagnetic Structures

TL;DR

This paper shows how shape-induced strain can be used to control antiferromagnetic order in NiO/Pt thin films, revealing a new method to tailor antiferromagnetic device properties through geometric design.

Contribution

It introduces a modeling approach linking shape-induced strain to antiferromagnetic domain control, advancing the understanding of magnetoelastic interactions in thin films.

Findings

Shape-dependent strain influences antiferromagnetic domain structures.

Aspect ratio variations can control the antiferromagnetic ground state.

Magnetoelastic interactions are key to domain configuration control.

Abstract

We demonstrate how shape-induced strain can be used to control antiferromagnetic order in NiO/Pt thin films. For rectangular elements patterned along the easy and hard magnetocrystalline anisotropy axes of our film, we observe different domain structures and we identify magnetoelastic interactions that are distinct for different domain configurations. We reproduce the experimental observations by modeling the magnetoelastic interactions, considering spontaneous strain induced by the domain configuration, as well as elastic strain due to the substrate and the shape of the patterns. This allows us to demonstrate and explain how the variation of the aspect ratio of rectangular elements can be used to control the antiferromagnetic ground state domain configuration. Shape-dependent strain does not only need to be considered in the design of antiferromagnetic devices, but can potentially be used to tailor their properties, providing an additional handle to control antiferromagnets.