1. Forschungszentrum Jülich GmbH; Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1); D-52425 Jülich Germany
2. Jülich Aachen Research Alliance; JARA-Energy; D-52425 Jülich Germany
3. Forschungszentrum Jülich GmbH; Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons; D-52425 Jülich Germany
4. Materials Science & Technology Division; Oak Ridge National Laboratory; Oak Ridge Tennessee 37831