Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 26: Ultrafast Magnetization Effects I
MA 26.8: Vortrag
Mittwoch, 19. März 2025, 17:00–17:15, H16
Development of planar micro optics for ultrafast in-situ measurements in the TEM — •Max Herzog1, Johannes Schultz1, and Axel Lubk1,2 — 1IFF, IFW Dresden, Helmholtzstraße 20, 01069 Dresden — 2IFMP, TU Dresden, Haeckelstraße 3, 01069 Dresden
The miniaturization of magnetic electron optics has been a goal for at least the past decade, because it will not only allow for smaller and easier to build electron optics, but will also result in other favorable scaling effects. Namely, the small scale allows for magnetic flux densities in the hundreds of millitesla with a significantly reduced power consumption and lower overall complexity regarding vacuum, cooling and power supply. More important for this work, however, is the small inductance that follows from the small size, which in turn allows the optics to be switched with radio frequencies (RF). The aim of this work is to lithographically produce planar micro optics (e.g. deflectors, focusing quadrupoles, vector magnets, etc.), that are capable of utilizing this RF switching to image ns-scale processes (e.g. the movement of magnetic domain walls) stroboscopically in a transmission electron microscope. The optics were characterized using differential phase contrast (DPC) to determine the spatial distribution of the magnetic field and by measuring the optical power (e.g. deflection, focusing behaviour) at varying switching frequencies. Using an acceleration voltage of 80 kV, the optics show a promising performance with a deflection power of up to 330 µrad at an excitation frequency of 7.5 MHz and still 120 µrad at 2 GHz with a very homogeneous magnetic field as determined by DPC.
Keywords: Transmission Electron Microscopy; Ultrafast Microscopy; Micro Electro-Mechanical Systems