Abstract
Magnetic skyrmions are promising candidates for the next generation of spintronic devices due to their small size and topologically protected structure. One challenge for using these magnetic states in applications lies on controlling the nucleation process and stabilization that usually requires an external force. Here, we report on the evidence of skyrmions in unpatterned symmetric Pd/Co/Pd multilayers at room temperature without prior application of neither electric current nor magnetic field. Decreasing the ferromagnetic interlayer thickness, the tuning of the physical properties across the ferromagnetic/non-magnetic interface gives rise to a transition from worm like domains patterns to isolated skyrmions as demonstrated by magnetic force microscopy. On the direct comparison of the measured and simulated skyrmions size, the interfacial Dzyaloshinskii-Moriya interaction (iDMI) was estimated, reveling that isolated skyrmions are just stabilized at zero magnetic field taking into account non-null values of iDMI. Our findings provide new insights towards the use of stabilized skyrmions for room temperature devices in nominally symmetric multilayers.
Highlights
The full control of the magnetization processes in small-sized magnetic states is essential to increase the density of information in magnetic memories[1,2,3]
We demonstrate that magnetic skyrmions can be stabilized at room temperature in unpatterned samples without the need for any preceding external excitation nor geometric confinement
We observed the formation of skyrmions in both as-grown and remnant states of nominally symmetric Pd/Co/Pd multilayers when the Co thickness is as thin as the percolation threshold of a continuous layer
Summary
Two iden- tical samples were grown in each sputtering process in order to acquire MFM images at zero magnetic field and magnetization curves. We operated the MFM measurements at the dynamic force mode with a resonant frequency of about 75 kHz. The images were acquired in the tip-surface distance of 60 nm. To acquire images in different areas, we moved the sample over distances of 1 mm in order to confirm the homogeneity of the domain magnetic patterns. The long time 1 μs, to carry out the simulations, was chosen in order to verify if the skyrmions would persist after being stabi- lized. No transformation after their stability was observed. Comparable results were obtained regarding the ferromagnetic order and skyrmions stability
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
