1. Central Facility for Electron
Microscopy, Group of Electron Microscopy of Materials Science, Ulm University, 89081 Ulm, Germany
2. Department of Physics, University of Helsinki, P.O. Box 43, 00014 Helsinki,
Finland
3. Department of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna,
Austria
4. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569
Stuttgart, Germany
5. Institute
of Micro and Nanomaterials, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm,
Germany
6. Department of Applied
Physics, Aalto University, P.O. Box 1100,
00076 Aalto, Finland