The control of domain walls or spin textures is crucial for spintronic applications of antiferromagnets. Despite many efforts, it has been challenging to directly visualize antiferromagnetic domains or domain walls with nanoscale resolution, especially in magnetic field. Here, we report magnetic imaging of domain walls in several uniaxial antiferromagnets, the topological insulator MnBi2Te4 family and the Dirac semimetal EuMnBi2, using cryogenic magnetic force microscopy (MFM). Our MFM results reveal higher magnetic susceptibility or net moments inside the domain walls than in domains. Domain walls in these antiferromagnets form randomly with strong thermal and magnetic field dependences. The direct visualization of domain walls and domain structure in magnetic field will not only facilitate the exploration of intrinsic phenomena in topological antiferromagnets, but also open a new path toward control and manipulation of domain walls or spin textures in functional antiferromagnets.
@article{arxiv.1910.06488,
title = {Magnetic imaging of antiferromagnetic domain walls},
author = {Paul M. Sass and Wenbo Ge and Jiaqiang Yan and D. Obeysekera and J. J Yang and Weida Wu},
journal= {arXiv preprint arXiv:1910.06488},
year = {2020}
}