Magnetization reversal and skyrmion transformation in magnetic multilayers

Chun-Yen Chen¹, Yen-Yun Lin², Yu-Hui Tang¹, Xin Fan³, Sy-Hwang Liou⁴, Jhen-Yong Hong^5*

¹Department of Physics, National Central University, Taoyuan 32001, Taiwan
²Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
³Department of Physics & Astronomy, University of Denver, Denver, CO 80208, USA
⁴Department of Physics & Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
⁵Department of Physics, Tamkang University, New Taipei City 251301, Taiwan

* Presenter:Jhen-Yong Hong, email:jyhong@mail.tku.edu.tw

We report a study of magnetization reversals and skyrmion transformations for topological spin textures in Co/Pd multilayers, in which magnetic skyrmions are stabilized by Dzyaloshinskii–Moriya interactions (DMIs). A generalized description of domain transformations associated with the first-order reversal curve (FORC) form an invaluable bridge linking the microscopic evolution of magnetization obtained by magnetic force microscopy (MFM) and macroscopic magneto-transport properties characterized by the anomalous Hall effect (AHE). Tracking the FORC distribution diagram at which the stripe domain transitions to skyrmions shows that the transition exhibits a macroscopic signature of irreversibility. In addition, a temperature-modulated FORC distribution shows that the macroscopic irreversibility and the microscopic skyrmion transformation are governed by thermodynamics, and in turn, determines chiral domain stability. Our study expands on the utility of FORC analysis for characterizing spin topology in multilayer thin films.

Keywords: Skyrmion, first-order reversal curve (FORC), Dzyaloshinskii–Moriya interactions (DMIs), anomalous Hall effect (AHE), magnetic force microscopy (MFM)