Role of substrate clamping on anisotropy and domain structure in the canted antiferromagnet α-Fe2O3

Antiferromagnets have recently been propelled to the forefront of spintronics by their high potential for revo-lutionizing memory technologies. For this, understanding the formation and driving mechanisms of the domain structure is paramount. In this work, we investigate the domain structure in a thin-film canted antiferromagnet alpha-Fe2O3. We find that the internal destressing fields driving the formation of domains do not follow the crystal symmetry of alpha-Fe2O3, but fluctuate due to substrate clamping. This leads to an overall isotropic distribution of the Neel order with locally varying effective anisotropy in antiferromagnetic thin films. Furthermore, we show that the weak ferromagnetic nature of alpha-Fe2O3 leads to a qualitatively different dependence on the magnetic field compared to collinear antiferromagnets such as NiO. The insights gained from our work serve as a foundation for further studies of electrical and optical manipulation of the domain structure of antiferromagnetic thin films.

Automated summary

This study investigates the domain structure in a thin-film canted antiferromagnet alpha-Fe2O3, finding that the internal destressing fields driving domain formation are influenced by substrate clamping rather than following crystal symmetry. It is also shown that the weak ferromagnetic nature of alpha-Fe2O3 leads to a qualitatively different response to magnetic fields compared to collinear antiferromagnets. These insights lay the foundation for further research on electrical and optical manipulation of the domain structure in antiferromagnetic thin films.