1. Institute of Materials Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
2. Graz Centre for Electron Microscopy (ZFE), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
3. Institute of Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
4. Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria