Ferromagnetism observed in pristine SnO2 thin films

Room temperature ferromagnetism (FM) was observed in laser ablated undoped SnO2 thin films grown on LaAlO3 substrates (the saturated magnetization is about 12 emu/cm(3), as half of that of the TiO2 films with the same thickness). Experiments on Mn-doped SnO2 films show that a transition-metal doping does not play any key role in introducing FM in the system. Mn doping (even if with a small content), in fact, just degrades the structure of the SnO2 host and, as a consequence, reduces its magnetic moment. Both oxygen vacancies and confinement effects are assumed to be key factors in introducing magnetic ordering into SnO2.