Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 11: Focus: Advanced TEM spectroscopy - low energy excitations and chemical composition at high resolution (joint session KFM/HL)

HL 11.1: Hauptvortrag

Montag, 1. April 2019, 15:00–15:30, PHY 5.0.20

Fifteen years of electron magnetic circular dichroism — •Ján Rusz — Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden

Electron magnetic circular dichroism (EMCD; [1]) has been proposed in 2003 and for the first time experimentally realized in 2006. Since then the method went through a rapid development at both fronts - experimental and theoretical. Dynamical diffraction effects severely complicate EMCD detection and often reduce the its strength. To circumvent this, numerous ways of acquiring EMCD have been proposed and many of them were experimentally tested. Recently, EMCD was detected using astigmatic electron beams on antiferromagnets, or with convergent probes, resolving magnetic signals from areas smaller than a square nanometer. In high-resolution TEM setting, EMCD signal from individual atomic planes was detected using the PICO instrument, where a crucial role was played by chromatic aberration corrector. Theory predicts that electron vortex beams should be efficient probes of EMCD at atomic resolution. Successful realization of this experiment could be extended further to probe the third dimension by means of magnetic depth sectioning. We will review the recent history of EMCD, its present state-of-art and discuss some of its challenges for the near future.

[1] P. Schattschneider et al., Nature 441, 486 (2006).