Epitaxial growth and experimental study of Cr₂O₃ Thin Films

Antiferromagnetic thin films hold much promise for the future of spintronics, not only as media to enhance spin transport but as sources of spin current in nano-devices as well. Synthesis of antiferromagnetic thin films and obtaining near perfect crystalline quality is essential to understanding and controlling spin related phenomena. In this work, we have explored the epitaxial growth of Cr₂O₃ antiferromagnetic thin films on Al₂O₃ substrates using pulsed laser deposition under various growth and post-growth annealing conditions with different crystal orientations. The Cr₂O₃ thin films are characterized by both in-situ (e.g., RHEED) and ex-situ (e.g., HRXRD, XPS, AFM). Under the optimal conditions, we have obtained atomically smooth surface in (11-20)-oriented epitaxial films with well-defined Neel temperature ~ 305 K. Spin Seebeck effect (SSE) responses seem to show correlation with the film structural quality.



This work was supported in-part by NSF/DMR award #2203134.