Three-Dimensional Vortex Gyration Dynamics Unraveled by Time-Resolved Soft X‑ray Laminography with Freely Selectable Excitation Frequencies

• Published in: Nano letters Vol. 22; no. 5; pp. 1971 - 1977
• Main Authors: Finizio, Simone, Donnelly, Claire, Mayr, Sina, Hrabec, Aleš, Raabe, Jörg
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.03.2022
• Subjects: scanning transmission X-ray microscopy; 3D time-resolved magnetic imaging; laminography; magnetic vortex gyration; magnetization dynamics
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/acs.nanolett.1c04662

The imaging of magneto-dynamical processes has been, so far, mostly a two-dimensional business, also due to the constraints of the available experimental techniques. In this paper, building on the recent developments of soft X-ray magnetic laminography, we present an experimental setup where magneto-dynamical processes can be resolved in all three spatial dimensions and in time at arbitrary frequencies. We employ this setup to investigate two resonant dynamical modes of a CoFeB microstructure, namely, the fundamental vortex gyration mode and a magnetic field-induced domain wall excitation mode. For the former, we observe a large variation of the gyration dynamics across the thickness of the core, coexisting with a breathing mode of the vortex core. For the latter, we observe a uniform displacement of the domain walls across the thickness of the microstructure. The imaging of these two modes establishes the possibility to freely select the excitation frequency for soft X-ray time-resolved laminography, allowing for the investigation of resonant magneto-dynamical processes.