1. Max Planck Institute for Intelligent Systems, Stuttgart Center for Electron Microscopy, Heisenbergstrasse 3, 70569 Stuttgart, Germany
2. JEOL Ltd., 1-2 Musashino, 3-Chome Akishima, 196-8558 Tokyo, Japan
3. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany