Professor of Physics Xuemei M. Cheng and Alums Co-Author Article, Dec. 2022

The Effects of Field History on Magnetic Skyrmion Formation in [Pt/Co/Ir]₃ Multilayers

Authors: Andy T. Clark, Ph.D. '22; Xiao Wang, Ph.D. '20; A.R. Stuart; Q. Wang; W. Jiang; J.E. Pearson; S.G.E. te Velthuis; A. Hoffmann; Xuemei M. Cheng; K.S. Buchanan

Source: Journal of Magnetism and Magnetic Materials, Volume: 563, Article Number: 169951, DOI: 10.1016/j.jmmm.2022.169951, Dec. 2022

Type of Publication: Journal Article

Abstract: We report on the formation of Néel-type magnetic bubble skyrmions at room temperature in [Pt/Co/Ir]₃ multilayered thin films after an in-plane magnetic field treatment. Polar magneto-optical Kerr Effect (p-MOKE) microscopy images show that the dendritic magnetic configurations observed after AC demagnetization evolve into magnetic bubble skyrmions after the application and subsequent removal of an in-plane magnetic field. Micromagnetic simulations were used to systematically investigate the role of the in-plane magnetic field magnitude, misalignment of the sample, and the Dzyaloshinskii-Moriya interactions (DMI) in generating bubble skyrmions during the field treatment. The simulations show that in-plane fields slightly below the saturation field are the most effective at producing skyrmions, and, furthermore, a small field angle away from the sample plane not only leads to improved skyrmion formation but also provides a means to select the skyrmion polarity where the direction of the out-of-plane component of the field is opposite to the direction of the skyrmion cores. This field treatment scheme leads to a simple and reliable way to create magnetic bubble skyrmions in multilayered thin films with DMI.

Xuemei M. Cheng is dean of graduate studies and professor of physics.