Identifying the domain-wall spin structure in antiferromagnetic NiO/Pt

The understanding of antiferromagnetic domain walls, which are the interface between domains with different Neel order orientations, is a crucial aspect to enable the use of antiferromagnetic materials as active elements in future spintronic devices. In this work, we demonstrate that in antiferromagnetic NiO/Pt bilayers arbitraryshaped structures can be generated by switching driven by electrical current pulses. The generated domains are T domains, separated from each other by a domain wall whose spins are pointing toward the average direction of the two T domains rather than the common axis of the two planes. Interestingly, this direction is the same for the whole domain wall indicating the absence of strong Lifshitz invariants. The domain wall can be micromagnetically modeled by strain distributions in the NiO thin film induced by the MgO substrate, deviating from the bulk anisotropy. From our measurements we determine the domain-wall width to have a full width at half maximum of A = 98 +/- 10 nm, demonstrating strong confinement.

Automated summary

In this study, we demonstrate that arbitrary-shaped T domains can be generated in antiferromagnetic NiO/Pt bilayers through switching driven by electrical current pulses. The domain walls between the T domains have spins pointing towards the average direction of the two T domains, indicating the absence of strong Lifshitz invariants. The micromagnetic modeling suggests that the domain wall is formed by strain distributions in the NiO thin film induced by the MgO substrate.