1. Amirkhanov Institute of Physics, Daghestan Scientific Center, Russian Academy of Sciences (RAS), 367003 Makhachkala, Russia
2. Department of Physics and Astronomy, Box 516, Uppsala University, Uppsala SE-75120, Sweden
3. Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
4. Kurnakov Institute of General and Inorganic Chemistry, RAS, 119991 Moscow, Russia
5. National University of Science and Technology MISiS, 119049 Moscow, Russia
6. Institute Laue-Langevin, Boîte Postale 156, 38042 Grenoble Cedex 9, France