1. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich, Wilhelm-Johnen-Strasse, 52428 Jülich, Germany
2. 2nd Institute of Physics, RWTH Aachen University, Templergraben 55, 52062 Aachen, Germany
3. Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
4. Institute of Biological and Medical Imaging, Helmholtz Zentrum München, 85764 Neuherberg, Germany