[1] Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań, Poland
[2] Department of Physics, Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
[3] Laboratory of Magnetism, Institute of Experimental Physics, University of Bialystok, ul. Lipowa 41, 15-950 Bialystok, Poland