Structural, optical, and magnetic properties of the ferromagnetic semiconductor hematite-ilmenite Fe2-xTixO3-δ thin films on SrTiO3(001) prepared by pulsed laser deposition

Structural, electrical, and magnetic properties of epitaxial thin films of Fe1.5Ti0.5O3−δ grown by pulsed laser deposition on SrTiO3(001) have been studied. For all the investigated range of preparation conditions, the thin films are single phase. The films prepared using oxygen pressure PO2 above 3×10−7 Torr presents a R(3¯)c symmetry structure. A single phase with the R(3¯) symmetry is obtained for the substrate temperature Ts=730 °C and PO2=2.6×10−7 Torr. This sample showed a ferrimagnetic behavior with Curie temperature Tc above room temperature, with a high magnetic moment of 0.6 μB/formula at 300 K. The film containing the disordered R(3¯)c phase is weakly ferromagnetic, with a spin glass-like signature. Optical properties seem to be governed more by the oxygen vacancies induced during the growth, than by the atomic ordering of titanium.