Charge-carrier mediated ferromagnetism in Mo-doped In2O3 films

We investigated the correlation between the ferromagnetism and electric resistivity of Mo-doped (3-10 at. %) In2O3 films. We find that the saturation magnetization increases with the Mo concentration until it reaches its maximum at 7 at. % Mo doping (7.1 emu/cm(3)), after which it rapidly decreases upon higher doping concentration. Interestingly, the resistivity reveals opposite behavior with the Mo concentration, showing a minimum value at 7 at. % Mo doping. According to the temperature-dependent resistivity and the Hall effect measurements, we find that the samples with higher magnetization show metallic behavior with higher electron concentration. Notably, the samples show a linear relationship between the carrier concentration and the degree of magnetization. We believe the ferromagnetism in Mo-doped In2O3 is ascribed to the indirect exchange interaction mediated by the charge carriers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4722928]