Measurement of electronic structure at nanoscale solid-solid interfaces by surface-sensitive electron spectroscopy

Abstract

We explore the use of electron spectroscopy that samples the near-surface region of a crystal to study the electronic structure at the buried interfaces between two dissimilar transition-metal oxides. The interface is probed by comparing experimental ultraviolet photoelectron spectra to model spectra and by taking sequential differences between the experimental spectra as one oxide is grown on another. Using (100) Fe3O4–NiO and Fe3O4–CoO interfaces grown by molecular beam epitaxy, we show that there is a much higher density of electronic states at the Fe3O4–CoO interface than at the Fe3O4–NiO interface. The origin of this difference is discussed.