1. Centre
of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie-Sklodowskiej 34, Zabrze 41-819, Poland
2. A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka
4, Katowice 40-007, Poland
3. Faculty
of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Reymonta 4, Krakow 30-059, Poland
4. Faculty
of Materials Science and Ceramics, AGH University of Science and Technology, Mickiewicza 30, Krakow 30-059, Poland