1. Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
2. Zernike Institute for Advanced Materials and Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
3. Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, DK-2800 Kongens Lyngby, Denmark