Identifiying the domain wall spin structure in current-induced switching of antiferromagnetic NiO/Pt

• Main Authors: Schmitt, Christin, Sanchez-Tejerina, Luis, Filianina, Mariia, Fuhrmann, Felix, Meer, Hendrik, Ramos, Rafael, Maccherozzi, Francesco, Backes, Dirk, Saitoh, Eiji, Finocchio, Giovanni, Baldrati, Lorenzo, Kläui, Mathias
• Format: Journal Article
• Language: English
• Published: 05-09-2022
• Subjects: Physics - Materials Science
• DOI: 10.48550/arxiv.2209.02040

The understanding of antiferromagnetic domain walls, which are the interface
between domains with different N\'eel 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 circular domain 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 circular domain
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
$\Delta = 98 \pm 10$ nm, demonstrating strong confinement.