Berlin 2015 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 19: POSTER Ia
MA 19.34: Poster
Dienstag, 17. März 2015, 09:30–13:00, Poster A
Lorentz microscopy of laser-induced vortex formation in microstructures — •Tim Eggebrecht1, Jan Gregor Gatzmann2, Vladyslav Zbarsky3, Sascha Schäfer2, Claus Ropers2, Markus Münzenberg3, and Konrad Samwer1 — 1I. Physikalisches Institut, Universität Göttingen — 2IV. Physikalisches Institut, Universität Göttingen — 3Grenz- und Oberflächenphysik, Universität Greifswald
For many years magnetic microstructures have been used for storing data in the hard drive industry. Several new methods were developed in order to save bits faster and with higher density in space. We present one of these potential methods in this work.
To produce magnetic microstructures, we show the focused ion beam method on thin Si3N4 membranes. Magnetically soft CoFeB thin films are capable to achieve a predictable long-range magnetic order. Thereby, we are able to investigate single magnetic vortices caused by shape anisotropy in single elements. We used a modified transmission electron microscope (TEM) to introduce a laser beam, which can be positioned on the sample. The laser system facilitates single femtosecond pulses and the Lorentz imaging mode of the TEM provides a direct observation of change in magnetization. After excitation with a single pulse, we see a reversing in rotation of vortices to the opposite. Furthermore, we examine the dependence on shape and size of the microstructures of this process.
We acknowledge support by the DFG via SFB 1073.