1. Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
2. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
3. Material Science and Technology Division, Oak Ridge Laboratory, Oak Ridge, Tennessee 37831, United States
4. Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
5. Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
6. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
7. Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland