1. Nanomaterials Group, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto, Finland
2. Department of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
3. Department of Physics, University of Helsinki, P.O. Box 43, 00014 University of Helsinki, Finland
4. LMA, Instituto de Nanociencia de Aragon, U. Zaragoza, c/Mariano Esquillor, 50018 Zaragoza, Spain
5. Fundacion ARAID, 50004 Zaragoza, Spain
6. LEM, UMR 104 CNRS-ONERA, 29 avenue de la Division Leclerc, 92322 Châtillon, France
7. Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm, Germany
8. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
9. LPS, UMR 8502 CNRS, Université Paris Sud XI, Bâtiment 510, F 91405 Orsay, France
10. Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Finland