1. Department of Electronic and Electrical Engineering, University of Sheffield 1 , Sheffield S1 4DE, United Kingdom
2. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Juelich 2 , 52425 Juelich, Germany
3. Institute of Solid State Physics, TU Wien 3 , 1040 Wien, Austria
4. University Service Centre for Transmission Electron Microscopy, TU Wien 4 , 1040 Wien, Austria
5. Diamond Light Source, Diamond House, Harwell Science and Innovation Campus 5 , Didcot OX11 0DE, United Kingdom