1. Solid State Physics Section, Institute of Physics - Center for Science and Education, Silesian University of Technology, Z. Krasińskiego 8, 40-019 Katowice, Poland
2. Institute of Materials Science, University of Silesia, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
3. Department of Materials Science, Silesian University of Technology, Z. Krasińskiego 8, 40-019 Katowice, Poland