Room-temperature ferromagnetism in epitaxial Mg-doped SnO2 thin films

The magnetic behavior of epitaxial Mg-doped SnO2 thin films prepared by radio-frequency magnetron sputtering was investigated in this work. Room-temperature ferromagnetism with the saturation magnetization of about 6.9 emu/cm(3) was observed in 6% Mg-doped SnO2 samples. And the saturation magnetization decreases when further doped to 8%, while the optical band-gap increases. The room-temperature ferromagnetism was induced by the holes created by Mg on the substitutional site. Additionally, Mg interstitials and oxygen vacancies play an important role in reducing the magnetic moments. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4711220]