Fe-doped In2O3 films with well defined bec (440) texture were grown on r-cut sapphire at different oxygen pressures by pulsed laser deposition. Nonmonotonic dependence of ferromagnetism on oxygen pressure has been observed. Under optimal deposition conditions, the saturation magnetization can reach 2.5 mu(B)/Fe atom. Moreover, the ferromagnetism can be reversed between the higher magnetization state and the lower magnetization state by alternate annealing in vacuum and in air. All these features are well explained by a modified model of F-center mediated ferromagnetism. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3202287]