Current-induced switching of thin film -Fe₂O₃ devices imaged using a scanning single-spin microscope

Electrical switching of Neel order in an antiferromagnetic insulator is desirable as a basis for memory applications. Unlike electrically driven switching of ferromagnetic order via spin-orbit torques, electrical switching of antiferromagnetic order remains poorly understood. Here we investigate the low-field magnetic properties of 30-nm-thick, c-axis-orienteda-Fe2O3 Hall devices using a diamond nitrogen-vacancy center scanning microscope. Using the canted moment of alpha-Fe2O3 as a magnetic handle on its Neel vector, we apply a saturating in-plane magnetic field to create a known initial state before letting the state relax in low field for magnetic imaging. We repeat this procedure for different in-plane orientations of the initialization field. We find that the magnetic field images are characterized by stronger magnetic textures for fields along [1 over bar 1 over bar 20] and [112 over bar 0], suggesting that despite the expected 3-fold magnetocrystalline anisotropy, our alpha-Fe2O3 thin films have an overall in-plane uniaxial anisotropy. We also study current-induced switching of the magnetic order in alpha-Fe2O3 We find that the fraction of the device that switches depends on the current pulse duration, amplitude, and direction relative to the initialization field.