1. Belarusian State University of Informatics and Radioelectronics, P. Brovka 6, 220013 Minsk, Belarus
2. Scientific and Practical Materials Research Center of NAS of Belarus, P. Brovka 19, 220072 Minsk, Belarus
3. Institute of Applied Physics, Academy of Sciences of Moldova, Academiei 5, MD 2028, Chisinau, Republic of Moldova
4. Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, 04103 Leipzig, Germany