A journey into the tuneable antiferromagnetic spin textures of BiFeO3

TL;DR

This paper demonstrates the imaging and control of diverse, tunable antiferromagnetic spin textures in BiFeO3 thin films, revealing their potential for reconfigurable spintronic devices through strain and electric field manipulation.

Contribution

It provides the first detailed visualization and control of various antiferromagnetic textures at the submicron scale in BiFeO3, using advanced microscopy and scattering techniques.

Findings

Strain stabilizes different antiferromagnetic states.

Electric fields induce transitions between magnetic textures.

Room temperature magnetoelectric coupling enables reconfigurability.

Abstract

Antiferromagnetic thin films are currently generating considerable excitement for low dissipation magnonics and spintronics. However, while tuneable antiferromagnetic textures form the backbone of functional devices, they are virtually unknown at the submicron scale. Here we image a wide variety of antiferromagnetic spin textures in multiferroic BiFeO3 thin films that can be tuned by strain and manipulated by electric fields through room temperature magnetoelectric coupling. Using piezoresponse force microscopy and scanning NV magnetometry in self-organized ferroelectric patterns of BiFeO3, we reveal how strain stabilizes different types of non-collinear antiferromagnetic states (bulk-like and exotic spin cycloids) as well as collinear antiferromagnetic textures. Beyond these local-scale observations, resonant elastic X-ray scattering confirms the existence of both types of spin cycloids. Finally, we show that electric-field control of the ferroelectric landscape induces transitions either between collinear and non-collinear states or between different cycloids, offering perspectives for the design of reconfigurable antiferromagnetic spin textures on demand.