1. Department of Physics and Material Research, University of Economy, Garbary 2, 85-229 Bydgoszcz, Poland
2. Faculty of Food Sciences, University of Warmia and Mazury in Olsztyn, Oczapowskiego 7, 10719 Olsztyn, Poland
3. Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland
4. Faculty of Chemistry, University of Wroclaw, Joliot Curie 14, 50-383 Wroclaw, Poland
5. Institut für Festkörperphysik, TU Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
6. Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, 10710 Olsztyn, Poland