Mixed-Type Skyrmions in Symmetric Pt/Co/Pt Multilayers at Room Temperature

Min He; Tiankuo Xu; Yang Gao; Chaoqun Hu; Jianwang Cai; Ying Zhang

doi:10.3390/ma15228272

Mixed-Type Skyrmions in Symmetric Pt/Co/Pt Multilayers at Room Temperature

Materials (Basel). 2022 Nov 21;15(22):8272. doi: 10.3390/ma15228272.

Authors

Min He¹, Tiankuo Xu^{2

3}, Yang Gao², Chaoqun Hu², Jianwang Cai^{2

4}, Ying Zhang^{2

4

5}

Affiliations

¹ School of Physics and Electronic Information, Yantai University, Yantai 264005, China.
² Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
³ College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ Songshan Lake Materials Laboratory, Dongguan 523808, China.

Abstract

We demonstrate the generation of mixed-type skyrmions (all are about 200 nm) that are primarily Bloch-type, hybrid-type, and a negligible amount of Néel-type in symmetric Pt/Co(1.55)/Pt multilayers at room temperature. The magnetic field dependence of skyrmion evolution is reversible. Brillouin light-scattering is used to quantitatively quantify the Dzyaloshinskii-Moriya interaction constant D in order to comprehend the mechanism. Interestingly, the D value is high enough to generate skyrmions in a symmetric sandwich structure. Micromagnetic simulations show that Néel-type skyrmions transform into Bloch-type skyrmions as the D value decreases. The interface-induced non-uniform D may be the cause to generate mixed-type skyrmions. This work broadens the flexibility to generate skyrmions by engineering skyrmion-based devices with nominally symmetric multilayers without the requirement of very large DMI.

Keywords: DMI; magnetic skyrmions; symmetric multilayers.

Grants and funding

This research was funded by the National Natural Science Foundation of China under Grant No. 12004326, and Shandong Natural Science Funds for Doctoral Program under Grant No. ZR2019BA009.