1. School of Physics, University of Bristol, Bristol BS8 1TL, UK.
2. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
3. ENGIN-X, ISIS Facility, Rutherford Appleton Laboratory, Harwell Campus, Oxon OX11 0QX, UK.
4. Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA.
5. National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
6. School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia.
7. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
8. Materials Science and Engineering Department, University of Tennessee, Knoxville, TN 37996, USA.
9. Institute for Materials, Ruhr University Bochum, 44801 Bochum, Germany.