Deposition of iron oxide thin films by pulsed laser evaporation

Iron oxide films have been deposited on alumina substrates by pulsed ruby laser evaporation from a bulk α-Fe2O3 pellet. The films have been characterized by using the techniques of conversion electron Mössbauer spectroscopy, Rutherford backscattering, and scanning electron microscopy. It is demonstrated that the stoichiometry of the deposited film can be varied between FeO and Fe3O4 by controlling the oxygen partial pressure during deposition over a range from 5×10−7 to 10−4 Torr. It is further shown that the Fe3O4 film can be converted into γ-Fe2O3 by suitable thermal annealing treatment.