Electronic structure of ilmenite and ilmenite-hematite solid solution using hard X-Ray photoemission spectroscopy

We have conducted hard X-ray photoemission spectroscopy on FeTiO 3 and FeTiO3-Fe2O3 solid solution in order to examine the electronic structure and electrical conduction mechanism of the compounds. The valence band spectrum of FeTiO3-Fe2O3 solid solution manifests a clear peak shift compared to FeTiO3, indicating that the electronic structure of FeTiO3-Fe2O3 solid solution consists of strongly mixed Fe 3d and O 2p components and that the electron correlation of the Fe 3d components is varied by the formation of solid solution between FeTiO3 and a-Fe2O3. We propose that insulating FeTiO3 is converted into semiconductor via this mechanism by the formation of FeTiO3-Fe2O3 solid solution, and the electron transfer between Fe2+ and Fe3+ in C-plane dominantly contributes to the electrical conduction in FeTiO3-Fe2O3 solid solution.