Authors
Marta Przychodnia
Institute of Physics, Poznan University of Technology, ul. Piotrowo 3, 60-965, Poznan, Poland
Ryszard Czajka
Institute of Physics, Poznan University of Technology, ul. Piotrowo 3, 60-965, Poznan, Poland
Wojciech Koczorowski
Institute of Physics, Poznan University of Technology, ul. Piotrowo 3, 60-965, Poznan, Poland