1. Faculty of Physics and Technology, Department of Technical Physics, L.N. Gumilyov Eurasian National University, 2 Satpayev Str., Nur-Sultan 010000, Kazakhstan
2. Institute of Solid State Physics, University of Latvia, 1001-1084 Riga, Latvia
3. Institute of Energy and Mechanical Engineering, Satbayev University, Almaty 050040, Kazakhstan