1. Peter Grünberg Institut (PGI-7) and JARA-FIT, Forschungszentrum Jülich GmbH, Jülich 52425, Germany
2. RWTH Aachen University, Aachen 52062, Germany
3. JARA−FIT and Institute of Inorganic Chemistry, RWTH Aachen University, Aachen 52074, Germany
4. Faculty of Medical Engineering and Applied Mathematics, FH Aachen, University of Applied Science, 52428 Jülich, Germany