1. Ernst Ruska‐Centre, Forschungszentrum Jülich, 52425 Jülich (Germany)
2. Brazilian Nanotechnology National Laboratory, 13083‐970, Campinas, SP (Brazil)
3. Current position: International Iberian Nanotechnology Laboratory (INL), Braga (Portugal)
4. Department of Chemistry, Federal University of São Carlos, 13565‐905, São Carlos (Brazil)
5. Current position: Universidade Federal do Espírito Santo (UFES), São Mateus (Brazil)
6. Central Facility for Electron Microscopy, RWTH Aachen University, 52074 Aachen (Germany)