1. Institute of Solid State Physics, NAWI Graz, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
2. Graz Centre for Electron Microscopy (ZFE), Steyrergasse 17, 8010 Graz, Austria
3. Institute for Electron Microscopy and Nanoanalysis (FELMI), NAWI Graz, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria