Fe/BaTiO3 interface: Band alignment and chemical properties

Ultrathin BaTiO3/Fe bi-layers were synthesized on MgO(001) and SrTiO3(001) substrates by pulsed laser deposition in a single vacuum cycle. The full electronic band structure at the Fe/BaTiO3interface has been determined by hard x-ray photoemission spectroscopy measurements. Depending on the growth conditions, the valence and conduction band offsets are found 3.05-3.26 eV and 0.9-1.2 eV, respectively. Interface sensitive conversion electron Mößbauer spectroscopy demonstrates the absence of any magnetically dead layer thus proving that the determined band alignment is related to a sharp Fe/BaTiO3interface structure down to the atomic scale.