1. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum
Jülich GmbH, 52425 Jülich, Germany
2. Chemistry Department, Ben Gurion University of the Negev, Be’er Sheba,
Israel
3. Braun Center for Submicrometer
Research, Weizmann Institute of Science, Rehovot 76100, Israel