1. Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart, Germany
2. Max Planck Society Outstation at the Heinz Maier-Leibnitz Zentrum (MLZ), D-85748 Garching, Germany
3. Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow 119991, Russia
4. Institute of Electronic Engineering and Nanotechnologies ASM, MD2028 Kishinev, Moldova
5. Solid State Physics Department, Kazan Federal University, 420008 Kazan, Russia