1. Central Facility for Electron Microscopy GFE, RWTH Aachen University, 52074 Aachen, Germany
2. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
3. Physikalisch-Technische Bundesanstalt PTB, 38116 Braunschweig, Germany
4. Institute of Energy and Climate Research IEK-12, Forschungszentrum Jülich GmbH, 48149 Münster, Germany
5. Institute of Energy and Climate Research IEK-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
6. Faculty of Science and Technology, Inorganic Membranes, University of Twente, 7500 AE Enschede, The Netherlands