Efficient manipulation of antiferromagnetic (AF) domains and domain walls has opened up new avenues of research towards ultrafast, high-density spintronic devices. AF domain structures are known to be sensitive to magnetoelastic effects, but the microscopic interplay of crystalline defects, strain and magnetic ordering remains largely unknown. Here, we reveal, using photoemission electron microscopy combined with scanning X-ray diffraction imaging and micromagnetic simulations, that the AF domain structure in CuMnAs thin films is dominated by nanoscale structural twin defects. We demonstrate that microtwin defects, which develop across the entire thickness of the film and terminate on the surface as characteristic lines, determine the location and orientation of 180 degree and 90 degree domain walls. The results emphasize the crucial role of nanoscale crystalline defects in determining the AF domains and domain walls, and provide a route to optimizing device performance.
@article{arxiv.2110.03724,
title = {Defect-driven antiferromagnetic domain walls in CuMnAs films},
author = {Sonka Reimers and Dominik Kriegner and Olena Gomonay and Dina Carbone and Filip Krizek and Vit Novak and Richard P. Campion and Francesco Maccherozzi and Alexander Bjorling and Oliver J. Amin and Luke X. Barton and Stuart F. Poole and Khalid A. Omari and Jan Michalicka and Ondrej Man and Jairo Sinova and Tomas Jungwirth and Peter Wadley and Sarnjeet S. Dhesi and Kevin W. Edmonds},
journal= {arXiv preprint arXiv:2110.03724},
year = {2022}
}