Room-temperature zero-field tunable skyrmions in Pd/Co/Pd and Pd/Co/Mn/Pd multilayer thin films

Magnetic skyrmions are stable nanoscale magnetic domains with promising applications in low-power storage devices. Pd/Co/Pd multilayers have displayed magnetic skyrmions at room temperature and in the absence of an external field. Additionally, a previous initial study found potential skyrmions in Pt/Co/Mn multilayers. Here, we explore the magnetic domains of a novel Pd/Co/Mn/Pd system and compare them with those of Pd/Co/Pd. We observed a skyrmion density of ⁓7 skyrmions per square micrometer in the Pd/Co/Mn/Pd system and a significant increase from ⁓3 skyrmions per square micrometer in the Pd/Co/Pd system. The diameter of the skyrmions in the Pd/Co/Mn/Pd system was also higher: ⁓115 nm, compared to ⁓80 nm in the other system. Extensive theoretical simulations allowed us to compare our experimental results with quantified values of the systems’ magnetic properties. While the topological nature of the observed magnetic domains deserves further study, our findings show the potential of adding Mn in magnetic multilayers to increase the skyrmion size and number of skyrmions per area, a necessary step toward utilizing stable skyrmions for storage devices.