Stabilization of Antiferromagnetic Single Domain States in Hematite Through Substrate Engineering

Hematite (α-Fe₂O₃) is a canted antiferromagnet capable of hosting nanoscale topological solitons and ultrafast spin waves, making it a promising system for spintronics and magnonics. However, in thin films, the domain structure is dominated by the magnetoelastic effect, which typically favours multiple domains—an undesirable condition for devices requiring a uniform Néel vector. Here, we realise complete control of the antiferromagnetic state by engineering epitaxial thin-films on viscinal miscut substrates. While films grown on non-miscut substrates exhibit multidomain behaviour, those grown on vicinal substrates show monodomain states at temperatures above and below the Morin transition. The antiferromagnetic distribution was mapped across multiple length scales using linear dichroic X-ray vectorial imaging, X-ray spectroscopy, and spin transport. A macrospin model reproduces the field and temperature dependent X-ray and transport data, while micromagnetic studies capture the observed antiferromagnetic textures. These results demonstrate deterministic control of antiferromagnetic order in hematite, establishing a versatile platform for the design of reconfigurable, ultrafast, and topologically robust spintronic devices.