[1] Chelyabinsk State Univ, Chelyabinsk 454021, Russia
[2] RAS, Dagestan Sci Ctr, Inst Phys, Makhachkala, Russia
[3] Russian Acad Sci, Inst Met Phys, Ural Branch, Ekaterinburg 620219, Russia
[4] RAS, Inst Radioengn & Elect, Moscow 125009, Russia
[5] Tver State Univ, Tver 170000, Russia