1. Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
2. Department of Materials, Eidgenössische Technische Hochschule Zürich, 8092 Zürich, Switzerland
3. Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
4. Université Grenoble Alpes, CNRS, Institut Néel, 38042 Grenoble, France