Magnetic and Transport Properties of n-type Fe Doped In₂O₃ and ZnO Films

Transition metals (TM) doped oxides films are promising in dilute magnetic semiconductors applications. However, the hindrance of the further progress is that the mechanism of ferromagnetism is still not clear. Several controversial results have been reported. In this work, we reported that room temperature ferromagnetism can be found in Fe doped In₂O₃ films. Room temperature ferromagnetism can be correlated with the carrier concentrations of Fe doped In₂O₃ films. The most conductive (In_0.90, Fe_0.10)₂O₃ film with carrier concentration of 5.78 × 10¹⁹ cm^–3 showed the highest saturation magnetization (8.2 emu/cm³). The mechanism can be explained by the carrier mediated ferromagnetism. The intrinsic ferromagnetism of Fe doped In₂O₃ films can be tuned by Fe concentrations and oxygen vacancies. However, Fe doped ZnO films did not possess ferromagnetism at room temperature due to their low carrier concentrations (in the order of 10¹⁸ cm³).