Nanoscale control of perpendicular magnetic anisotropy, coercive force and domain structure in ultrathin Ru/Co/W/Ru films

Development of fast and energy-efficient spintronic devices requires novel nanoscaled materials with controllable magnetic properties. Here we show that the introduction of an ultrathin W interlayer between Co and Ru in Ru/Co/Ru films enables to preserve perpendicular magnetic anisotropy (PMA) and dramatically reduce the coercive force and size of magnetic domains. We find that the Ru/Co/W/Ru films with up to 0.35 nm of the nominal thickness of W have robust PMA. The observed formation of a dendritic domain structure with small domains having homochiral Néel domain walls is an indicator of the interfacial Dzyaloshinskii-Moriya interaction appearing in trilayers with asymmetrical interfaces. The inversion-symmetry-broken Ru/Co/W/Ru films are a potential host for nucleation and manipulation of non-trivial spin textures like chiral domain walls and skyrmions.