[1] Russian Acad Sci, Osipyan Inst Solid State Phys, Chernogolovka 142432, Moscow Oblast, Russia
[2] Russian Acad Sci, Chernogolovka Sci Ctr, Chernogolovka 142432, Moscow Oblast, Russia
[3] Derzhavin Tambov State Univ, Res Inst Nanotechnol & Nanomat, Tambov 392000, Russia