| 1. |
- Reimers, Sonka, et al.
(author)
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Defect-driven antiferromagnetic domain walls in CuMnAs films
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Journal article (peer-reviewed)abstract
- 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∘ and 90∘ 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.
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| 2. |
- Reimers, Sonka, et al.
(author)
-
Defect-driven antiferromagnetic domain walls in CuMnAs films
- 2023
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In: 2023 IEEE International Magnetic Conference - Short Papers, INTERMAG Short Papers 2023 - Proceedings. - 9798350338362
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Conference paper (peer-reviewed)abstract
- Antiferromagnetic (AF) materials offer a route to realising high-speed, high-density data storage devices that are robust against magnetic fields due to their intrinsic dynamics in the THz-regime and the lack magnetic stray fields. The key to functionality and efficiency is the control of AF domains and domain walls. Although AF domain structures are known to be sensitive to magnetoelastic effects, 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 microscopy and micromagnetic simulations, that the AF domain structure in CuMnAs thin films is dominated by nanoscale structural twin defects, which determine the location and orientation of 180° and 90° domain walls. The results emphasise the high sensitivity of the AF domain structure to the crystallographic nanostructure and provide a route to optimisng device performance.
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| 3. |
- Reimers, Sonka, et al.
(author)
-
Magnetic domain engineering in antiferromagnetic CuMnAs and Mn 2 Au
- 2024
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In: Physical Review Applied. - 2331-7019. ; 21:6
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Journal article (peer-reviewed)abstract
- Antiferromagnetic materials hold potential for use in spintronic devices with fast operation frequencies and field robustness. Despite the rapid progress in proof-of-principle functionality in recent years, there has been a notable lack of understanding of antiferromagnetic domain formation and manipulation, which translates to either incomplete or nonscalable control of the magnetic order. Here, we demonstrate simple and functional ways of influencing the domain structure in CuMnAs and Mn2Au, two key materials of antiferromagnetic spintronics research, using device patterning and strain engineering. Comparing x-ray microscopy data from two different materials, we reveal the key parameters dictating domain formation in antiferromagnetic devices and show how the nontrivial interaction of magnetostriction, substrate clamping, and edge anisotropy leads to specific equilibrium domain configurations. More specifically, we observe that patterned edges have a significant impact on the magnetic anisotropy and domain structure over long distances and we propose a theoretical model that relates short-range edge anisotropy and long-range magnetoelastic interactions. The principles invoked are of general applicability to the domain formation and engineering in antiferromagnetic thin films at large, which will hopefully pave the way toward realizing truly functional antiferromagnetic devices.
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