Room-Temperature Ferromagnetism in Fe/Sn-Codoped In₂O₃ Powders and Thin Films

Fe/Sn-codoped In₂O₃ powders and films are prepared by a vacuum annealing process and a pulsed laser deposition technique, respectively. The structural and magnetic properties of the samples are investigated. The obvious room-temperature ferromagnetism is observed in both (In_0.92Fe_0.05Sn_0.03)₂O₃ powders and films, but their magnetic behaviors are very different. The ferromagnetism of the vacuum-annealed powders is partially due to precipitated Fe₃O₄ impurity. By contrast, the ferromagnetism of the films is intrinsic and does not originate from any magnetic impurity, as confirmed by the extensive x-ray absorption spectroscopy and magnetization studies.