ELABORATION AND CHARACTERIZATION OF α-Fe2O3 THIN FILMS BY RADIO FREQUENCY SPUTTERING

Fe2O3 thin films were deposited on alumina substrates by using the physical vapor deposition technique “RF magnetron sputtering†. The impact of the thermal treatment on the structural, optical and morphological properties was systematically investigated. The results of the structural characterizations reveal that the elaborated thin films present a main peak whichcorresponds to the crystalline plane (104) of the hematite (α-Fe2O3). Furthermore, the Raman spectra confirm the existence of the hematite phase of the iron oxide. UV-Visible spectrophotometer analysis of Fe2O3 thin films before and after annealing shows that the transmittance increases with heat treatment. Moreover, the heat treatment at 500∘C significantly improves the absorption coefficient α, extinction coefficient k, refractive index n, and the band gap of Fe2O3 thin films. Furthermore, a spinel polarization change was found to be responsible for the ferrobehavior of Fe2O3 thanks to the lattice crystallinity enhancement. The density functional theory calculations demonstrate that the magnetic properties are very sensible to any induced strain in the Fe2O3 lattices.