Magnetic imaging of skyrmionic spin textures in transmission electron microscopy

Thibaud Denneulin and Fengshan Zheng
Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany

Skyrmions are whirl-like magnetic textures that are elementary building blocks of possible future low-power storage and logic devices. Lorentz transmission electron microscopy  (LTEM) allows the observation of magnetic skyrmions with nanometer spatial resolution. In this presentation, we will show LTEM studies of skyrmionic spin textures found in different magnetic systems such as Pt/Co/NiFe multilayer samples, Fe5GeTe2 van der Waals materials and FeGe single crystals. Pt/Co/NiFe multilayers form an out-of-plane magnetized system with interfacial Dzyaloshinskii-Moriya interactions (DMI). We will show images of Néel-type skyrmion bubbles obtained by tilting the sample with respect to the electron beam direction [1]. Fe5GeTe2 is van der Waals material with perpendicular magnetic anisotropy and a relatively high Curie temperature of 300 K. We will show images of type-II bubbles and type-I bubbles with two possible chiralities obtained in this system. Finally, we will show Bloch-type skyrmions in B20-type FeGe with bulk DMI. In particular, we will discuss the complexity of the three-dimensional spin texture of an individual magnetic skyrmion, which was embedded in an FeGe nanodisk [2].

[1] T. Denneulin et al., Microscopy and Microanalysis 27, 6, 1356-1365 (2021)
[2] F. Zheng et al. Physical Review Letters 119,197205 (2017)

The authors acknowledge funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement 856538 (project “3D MAGIC”).