1. Institute of Physics
2. University of Silesia
3. 40-007 Katowice
4. Poland
5. Silesian Center for Education and Interdisciplinary Research
6. 41-500 Chorzow
7. Group of Nanomaterials and Microsystems
8. Physics Department
9. Universitat Autònoma de Barcelona
10. 08193 Bellaterra
11. Spain