Fe/BaTiO3 interface: Band alignment and chemical properties

Abstract

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/BaTiO3 interface 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/BaTiO3 interface structure down to the atomic scale.