1. Faculty
of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
2. Institute of Physics Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw, Poland
3. Electrotechnical
Institute, Division of Electrotechnology and Materials Science, M. Sklodowskiej-Curie 55/61, 50-369 Wroclaw, Poland