1. I. Institute of Physics (IA), RWTH Aachen University, Aachen, Germany.
2. Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department, Technische Universität München, Lichtenbergstrasse 1, 85747 Garching, Germany.
3. Heraeus Holding GmbH, Heraeusstr.12-14, 63450 Hanau, Germany.
4. Chair of Metallic Materials, Saarland University, Campus C6.3, 66123 Saarbrücken, Germany.
5. Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85712, USA.
6. School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.