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MI: Fachverband Mikrosonden
MI 7: Poster: Microanalysis and Microscopy
MI 7.3: Poster
Wednesday, March 9, 2016, 18:00–20:00, Poster E
Generation of electron vortex beams and OAM selection using aberration-corrected probes for local EMCD measurements — Darius Pohl1, •Sebastian Schneider1,2, Pascal Gerhards1,2, Jan Rusz3, Jakob Spiegelberg3, Peter Tiemeijer4, and Bernd Rellinghaus1 — 1IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany — 2TU Dresden, Institute for Solid State Physics, D-01062 Dresden, Germany — 3Uppsala University, Department of Physics and Astronomy, SE-752 37 Uppsala, Sweden — 4FEI Company, PO Box 8066, 5600 KA Eindhoven, The Netherlands
Electron vortex beams (EVBs) carry a discrete orbital angular momentum (OAM), L, and are predicted to reveal magnetic dichroic in electron energy loss spectra upon interacting with magnetic samples. Since electron beams can be easily focused down to sub-nanometer diameters, this novel technique provides the possibility to quantitatively determine local magnetic properties with unrivalled lateral resolution. The generation of EVBs in the double aberration-corrected FEI Titan3 80-300 transmission electron microscope (TEM) is achieved by the implementation of spiral and dislocation-type apertures into the condenser lens system. The setup allows for scanning TEM investigations (STEM) with EVBs, whose OAM is selected by means of an additional discriminator aperture. New FIB cutting strategies facilitate the production for 50 µm wide and 1 µm thick high quality vortex apertures. The status quo of both experiments and simulations of the interaction of the EVB with L10-FePt nanomagnets will be presented.