1. Department of Magnetic Materials and Nanostructures Institute of Nuclear Physics Polish Academy of Sciences 31‐342 Krakow Poland
2. Faculty of Chemistry Jagiellonian University 30‐060 Kraków Poland
3. Academic Centre for Materials and Nanotechnology AGH University of Science and Technology 30‐059 Kraków Poland
4. Institute of Metallurgy and Materials Science Polish Academy of Sciences 30‐059 Kraków Poland
5. Institute of Physics Cracow University of Technology 30‐084 Kraków Poland