1. Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
2. Institute of Solid State Physics of the Russian Academy of Sciences - Chernogolovka, Moscow District, Academician Ossipyan str. 2, Chernogolovka 142432, Russia
3. Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
4. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
5. National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
6. Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland