1. Nuclear Physics of CAS, v.v.i., Husinec - Řež 130, 250 68 Řež, Czech Republic
2. Department of Physics, Faculty of Science, J. E. Purkinje University, Pasteurova 3544/1, 400 96 Usti nad Labem, Czech Republic
3. Department of Physics (MIFT), Messina University, Messina, Italy
4. Department of Solid State Engineering, Institute of Chemical Technology, Prague, Czech Republic