Identification of N\'eel vector orientation in antiferromagnetic domains switched by currents in NiO/Pt thin films

Understanding the electrical manipulation of antiferromagnetic order is a crucial aspect to enable the design of antiferromagnetic devices working at THz frequency. Focusing on collinear insulating antiferromagnetic NiO/Pt thin films as a materials platform, we identify the crystallographic orientation of the domains that can be switched by currents and quantify the Néel vector direction changes. We demonstrate electrical switching between different Tdomains by current pulses, finding that the Néel vector orientation in these domains is along [±1 ±1 3.8], different compared to the bulk <112̅> directions. The final state of the Néel vector n switching after current pulses j along the [1 ± 1 0] directions is n ∥ j. By comparing the observed Néel vector orientation and the strain in the thin films, assuming that this variation arises solely from magnetoelastic effects, we quantify the order of magnitude of the magnetoelastic coupling coefficient as b0 + 2b1 = 3 × 10 7 J m ⁄ . This information is key for the understanding of current-induced switching in antiferromagnets and for the design and use of such devices as active elements in spintronic devices.