1. G.V. Kurdyumov Institute for Metal Physics, NASU, 36 Acad. Vernadsky Boulevard, Kyiv 03680, Ukraine and Vasyl' Stus Donetsk National University, Vinnytsia 021021, Ukraine
2. O.O. Galkin Donetsk Institute of Physics and Engineering, 46 Nauki Ave., Kyiv 03680, Ukraine
3. Ioffe Physico-Technical Institute, RAS, St. Petersburg 194021, Russia