1. AGH University of Science and Technology , Faculty of Energy and Fuels, Department of Hydrogen Energy , Al. Mickiewicza 30, 30-059 Krakow , Poland
2. Magnetic Research Centre, Magneto Sp. z o.o. , Czestochowa , Odlewnikow 43, Poland
3. Czestochowa University of Technology , Czestochowa , Armii Krajowej 17, Poland