title: EMCD with an electron vortex filter: Limitations and possibilities.
abstract: We discuss the feasibility of detecting spin polarized electronic transitions with a vortex filter. This approach does not rely on the principal condition of the standard electron energy-loss magnetic chiral dichroism (EMCD) technique, the precise alignment of the crystal in order to use it as a beam splitter, and thus would pave the way for the application of EMCD to new classes of materials and problems, like amorphous magnetic alloys and interface magnetism. The dichroic signal strength at the L2, 3-edge of ferromagnetic Cobalt (Co) is estimated on theoretical grounds using a single atom scattering approach. To justify this approach, multi-slice simulations were carried out in order to confirm that orbital angular momentum (OAM) is conserved in amorphous materials over an extended range of sample thickness and also in very thin crystalline specimen, which is necessary for the detection of EMCD. Also artefact sources like spot size, mask tilt and astigmatism are discussed. In addition, the achievable SNR under typical experimental conditions is assessed.
authors.affiliation: Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria; University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria. Electronic address: thomas.schachinger@tuwien.ac.at.
authors.forename: T
authors.initials: T
authors.lastname: Schachinger
authors.affiliation: University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Löffler
authors.affiliation: University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Steiger-Thirsfeld
authors.affiliation: Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria; University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Stöger-Pollach
authors.affiliation: Institute for Metallic Materials, IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Institute for Metallic Materials, IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Pohl
authors.affiliation: Institute for Metallic Materials, IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Rellinghaus
authors.affiliation: Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria; University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Schattschneider