Due to their unique topological and dynamic properties skyrmions in magnetic materials offer attractive perspectives for future spintronic applications . Recently, it has been discovered that magnetic skyrmions of Néel-type symmetry cannot only occur in ultra-thin transition metal films at surfaces [2,3] but also in asymmetric multilayers due to strong Dzyaloshinskii-Moriya (DMI) interactions . We carry out first-principles calculations in order to study the stabilization mechanism of skyrmions in multilayers. Here, we predict the emergence of skyrmions in a new class of multilayers based on [4d/Fe2/5d]n, i.e. structures composed of Fe biatomic layers sandwiched between 4d- and 5d-transition-metal layers . In these composite structures, the exchange and the Dzyaloshinskii-Moriya interactions which control skyrmion formation can be tuned separately by the two interfaces. This allows engineering skyrmions as shown by density functional theory, Monte Carlo and spin dynamics simulations.
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