Room temperature control of axial and basal antiferromagnetic anisotropies using strain

Abstract

Antiferromagnetic materials are promising platforms for the development of ultra-fast spintronics and magnonics due to their robust magnetism, high-frequency relativistic dynamics, low-loss transport, and the ability to support topological textures. However, achieving deterministic control over antiferromagnetic order in thin films is a major challenge, due to the formation of multi-domain states stabilised by competing magnetic and destressing interactions. Thus, the successful implementation of antiferromagnetic materials necessitates careful engineering of their anisotropy. Here, we demonstrate strain-based robust control over multiple antiferromagnetic anisotropies and nanoscale domains in the promising spintronic candidate a-Fe2O3, at room temperature. By applying isotropic and anisotropic in-plane strains across a broad temperature-strain phase space, we systematically tune the interplay between magneto-crystalline and magneto-elastic interactions. We discover that strain-driven control steers the system towards an aligned antiferromagnetic state, whilst preserving topological spin textures, such as merons, antimerons and bimerons. We directly map the nanoscale antiferromagnetic order using linear dichroic scanning transmission X-ray microscopy integrated with in situ strain and temperature control. A Landau model and micromagnetic simulations reveal how strain reshapes the magnetic energy landscape. These findings suggest that strain could serve as a versatile control mechanism to reconfigure equilibrium or dynamic antiferromagnetic states on demand in a-Fe2O3, paving the way for next-generation spintronic and magnonic devices.