1. Sumy State University, R. Korsakov Str., 2, 40007, Sumy, Ukraine
2. Kharkov National University, Kharkov, Ukraine
3. Belgorod State University, Belgorod, Russia
4. National Institute for Material Science (NIMS), Sangen, Tsukuba, Japan
5. National Kharkov Technical University (KHPI)" country="Ukraine
6. Universität Halle, Institut für Physik, 06120 Halle, Germany
7. Lublin University of Technology, Nadbystrzycka 38A, 20-618 Lublin, Poland