1. Institute of Particle Technology; Friedrich-Alexander Universität Erlangen-Nürnberg; Cauerstrasse 4 D-91058 Erlangen Germany
2. Department of Chemistry and Physics of Materials; Paris-Lodron University Salzburg; Jakob-Haringer-Strasse 2a A-5020 Salzburg Austria
3. University Service Center for Transmission Electron Microscopy; Technische Universität Wien; Wiedner Hauptstrasse 8-10 A-1040 Vienna Austria