Regensburg 2019 – scientific programme

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MA: Fachverband Magnetismus

MA 30: Magnetic instrumentation and characterization

MA 30.3: Talk

Wednesday, April 3, 2019, 11:15–11:30, H53

Quantitative measurements of magnetic states in patterned permalloy disks using off-axis electron holography and model-based reconstruction of magnetisation — •Teresa Weßels¹, Simone Finizio², Patrick Diehle¹, Jan Caron¹, Andras Kovacs¹, Vadim Migunov^1,3, Jörg Raabe², and Rafal Dunin-Borkowski¹ — ¹Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany — ²Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland — ³Central Facility for Electron Microscopy (GFE) RWTH Aachen University, 52074 Aachen, Germany

The ability to image magnetic states in sub-micron-sized structures is of increasing importance for new emerging technologies. Here, we investigate intrinsic magnetisation states in permalloy disks using off-axis electron holography in an aberration transmission electron microscope. The disks were deposited onto electron-transparent SiN windows with diameters of 750 to 1500 nm and thicknesses of 50 to 200 nm. Magnetic induction maps were determined from the recorded off-axis electron holograms and used to show that the disks contained magnetic vortices at remanence. The projected in-plane magnetisation in each disk was reconstructed quantitatively using a model-based iterative reconstruction algorithm. A cross-sectional analysis of the disks revealed that they had slightly distorted bowl-like shapes. The relationship between the disk shapes and the three-dimensional nature of the resulting magnetic states will be discussed.