Determination of Dzyaloshinskii-Moriya Interaction in Hematite via Anisotropic Morin Transition Response to Magnetic Field*

Hematite (α-Fe₂O₃) is a notable antiferromagnetic material with unique spin properties that spurs intense research interest in the rapidly emerging field of antiferromagnetic spintronics. One of the intriguing characteristics is the spin reorientation transition, often known as the Morin transition, at a temperature of 260 K. This phenomenon is significantly influenced by the presence of the Dzyaloshinskii-Moriya (DM) interaction. In this work, we investigate the Morin transition in (10-10)-oriented hematite under applied magnetic fields by performing transport measurements in a hematite/Pt heterostructure device. The applied field stabilizes the easy-plane phase and consequently suppresses the Morin transition, which is corroborated by magnetometry measurements. Moreover, the field-induced Morin temperature suppression depends on the magnetic field orientation with respect to the direction of the Dzyaloshinskii-Moriya vector. Based on the field-dependent anisotropic responses of the Morin temperature, we reveal the critical role of and unambiguously determine the strength of the Dzyaloshinskii-Moriya interaction in hematite.