thin films*

Strain-induced magnetic anisotropy has long been studied to control magnetic properties of ferro- and ferri-magnetic thin films. However, in antiferromagnetic (AFM) thin films, the effect of epitaxial strain on magnetic anisotropy has not yet been experimentally investigated. Here we perform spin Seeback effect (SSE) measurements on epitaxial Cr₂O₃ thin films grown on Al₂O₃ substrates to demonstrate the presence of the strain-enhanced magnetic anisotropy. Different tensile strains produced by varying the film thickness and annealing temperatures are characterized by X-ray diffraction, which reveals a correlation between the epitaxial strain and resulting spin flop (SF) transition. From the SSE results of these films with different strains, we observe significantly enhanced SF fields compared to the reported bulk result. The large contrast in the SF fields between thin film and bulk Cr₂O₃ indicates the existence of strong strain-induced magnetic anisotropy due to the magnetoelastic effect. Therefore, the epitaxial strain can potentially tune the magnetic anisotropy and consequently spin dynamics in Cr₂O₃ and other AFM thin films for AFM spintronic applications.