1. Max Planck Institute for Solid State Research , Stuttgart , Germany
2. Department of Materials Sciences and Engineering, Cornell University , Ithaca, NY , USA
3. Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Erlangen , Germany
4. National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, CA , USA
5. Kavli Institute at Cornell for Nanoscale Science , Ithaca, NY , USA
6. Leibniz-Institut für Kristallzüchtung , Berlin , Germany