Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 16: Magnetic characterization techniques

MA 16.3: Vortrag

Dienstag, 13. März 2018, 10:00–10:15, H 0112

EMCD measurements with electron vortex beams on ferrimagnetic — •Darius Pohl¹, Sebastian Schneider¹, Jan Rusz², Jakob Spiegelberg², Peter Tiemeijer³, Sorin Lazar³, Xiaoyang Zhong⁴, Victor Brabers⁵, Kornelius Nielsch¹, and Bernd Rellinghaus¹ — ¹IFW Dresden — ²U Uppsala — ³Thermo Fisher Scientific — ⁴NCEM Beijing — ⁵U Eindhoven

Electron vortex beams (EVBs) carry a discrete orbital angular momentum (OAM), L, and are predicted to reveal electron energy loss magnetic chiral dichroism (EMCD) upon interacting with magnetic samples down to the atomic scale. Our optical setup allows for scanning TEM investigations (STEM) with vortex beams, whose OAM is selected by means of an additional discriminator aperture [1]. As a proof of principle experiment, two samples have been chosen, Sr₂FeMoO₆ and BaFe₁₁TiO₁₉. For both samples, an EMCD signal is found by principle component and vector component analysis (PCA and VCA) in the acquired spectra. However, local analysis still suffer from a low signal-to-noise ratio. The status quo of the experiments and simulations of the interaction of the EVB with the ferrimagnetic samples will be presented.
[1] D. Pohl, S. Schneider, P. Zeiger, J. Rusz, P. Tiemeijer, S. Lazar, K. Nielsch, B. Rellinghaus, Sci. Rep. 7 (2017) 934.