Regensburg 2022 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 19: Poster 1
MA 19.5: Poster
Dienstag, 6. September 2022, 17:30–20:00, P2
High-resolution in-situ mapping of magnetization dynamics — •Arsha Thampi1, 2, Felix Lucas Kern1, Yejin Lee1, Daniel Wolf1, Andy Thomas1, 2, and Axel Lubk1, 2 — 1Leibniz IFW Dresden, D-01069 — 2Institute for Solid State and Materials Physics, TU Dresden, D-01069
Mapping of magnetization dynamics at the nanometer scale, which includes domain wall motion and also study on magnetic textures like skyrmions, is performed with time resolved measurements using transmission electron microscopy (TEM). On-chip microsized magnetic charged particle optical elements were developed for spatiotemporal electron beam modulation. The employed micro-coils with a diameter of about 80 µ m are combined with soft-magnetic cores and arranged as dipoles and quadrupoles. These micro-electromagnets can generate alternating magnetic fields of about ±100 mT up to hundred MHz. They supply sufficiently large optical power and high-frequent beam manipulation to perform stroboscopic imaging. We discuss stroboscopic magnetization dynamics measurement employing either fast beam blanking or fast focusing. In order to study dynamics of magnetic structures, short electric pulses are applied by means of a sample holder that passes high frequencies. Current driven domain wall motion by spin torque effect is observed in a Nickel system by Lorentz TEM. The shift in domain walls is quantitatively analyzed depending on the current density and the heat deposited on the system. High-resolution mapping of magnetization dynamics can open the way to understand more on defects or pinning sites of domain wall.