X-ray characterization of surface and bulk structures of sputtered iron oxide thin film

The crystalline structures of a sputtered Co-doped iron oxide thin film have been successfully identified and correlated with magnetic properties. X-ray diffraction analysis showed that the bulk of the sputtered film has been properly converted to ferromagnetic γ-Fe2O3. However, the surface of the film was found to be solely hexagonal α-Fe2O3. The formation of an antiferromagnetic α-Fe2O3 surface on a ferromagnetic α-Fe 2O3 film caused the magnetically dead layer previously observed by polarized neutron reflection and Kerr rotation measurements.