1. Institute of Low Temperature and Structure Research
2. Polish Academy of Sciences
3. Poland
4. Department of Experimental Physics
5. Wrocław University of Technology
6. Wrocław
7. Faculty of Physics
8. Vilnius University
9. LT-10222 Vilnius
10. Lithuania
11. Faculdade de Fisica
12. Universidade Federal do Para
13. 66075-110 Belem
14. Brazil