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‐Fe2O3 film caused the magnetically dead layer previously observed by polarized neutron reflection and Kerr rotation measurements.