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Magnetic Imaging of Domain Walls in the Antiferromagnetic Topological Insulator MnBi2Te4
journal contribution
posted on 2020-03-05, 17:39 authored by Paul M. Sass, Wenbo Ge, Jiaqiang Yan, D. Obeysekera, J. J. Yang, Weida WuThe
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, using
cryogenic magnetic force microscopy (MFM). Our MFM results reveal
higher magnetic susceptibility inside the domain walls than in domains.
Domain walls in these antiferromagnets form randomly with strong thermal
and magnetic field dependence. The direct visualization of these domain
walls and domain structures in the magnetic field will not only facilitate
the exploration of intrinsic topological phenomena in antiferromagnetic
topological insulators but will also open a new path toward control
and manipulation of domain walls or spin textures in functional antiferromagnets.