AL-AL2O3 INTERFACE STUDY USING SURFACE SOFT-X-RAY ABSORPTION AND PHOTOEMISSION SPECTROSCOPY

The local structure and the electronic states of a thin oxide layer on a single-crystal Al (111) surface has been studied using surface soft-x-ray absorption and soft-x-ray photoemission spectroscopy. Unoccupied interface states are found in the oxide band gap. The local structure of the thin oxide layer is compared with the structure of bulk Al2O3. The effect on the electronic states of an amorphous to crystalline phase transition is shown. The crystalline oxide-metal interface has fewer unoccupied interface states in the Al2O3 gap than the amorphous oxide-metal interface. © 1979 The American Physical Society.