1. Department of Physics, Budapest University of Technology and Economics and Nanoelectronics ‘Momentum’ Research Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest, Hungary
2. Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296, Göteborg, Sweden
3. M.N. Miheev Institute of Metal Physics, Ural Branch of the Russian Academy of Science, 620108, Ekaterinburg, Russia
4. Ural Federal University, Ekaterinburg, 620002, Russia
5. Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Science, Ekaterinburg, 620990, Russia
6. St. Petersburg State University, 198504, St. Petersburg, Russia
7. A. V. Rzhanov Institute of Semiconductor Physics, 630090, Novosibirsk, Russia
8. Novosibirsk State University, 630090, Novosibirsk, Russia
9. V. S. Sobolev Institute of Geology and Mineralogy, 630090, Novosibirsk, Russia
10. Center for Energy Research, Institute of Technical Physics and Material Science, H-1121 Budapest, Hungary
11. National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan