Room temperature ferromagnetism studies in Fe ion implanted indium oxide films

Diluted magnetic semiconductor based on indium oxide has been prepared by Fe ion implantation. Pure In2O3 films are Fe ion implanted by metal vapor vacuum arc source with doses of 5×1015, 1×1016 and 4×1016 cm−2, respectively. The implanted samples are separately annealed in vacuum and O2 subsequently. The structure of In2O3 films is characterized by X-ray diffraction and high resolution transmission electron microscopy. X-ray photoelectron spectroscopy measurements are applied to research the electronic state of the implanted ions. Superconducting quantum interference device measurements at room temperature disclose that both pure and Fe implanted In2O3 films are ferromagnetic, and the ferromagnetism is enhanced with the increase of implantation dose. The ferromagnetic mechanism is discussed. The bound magnetic polarons formed by Fe ion implantation and the oxygen vacancy may be responsible for the observed results.