Electronic Structure of Aluminium Oxide as Determined by X‐Ray Photoemission

The electronic structure of the valence band of crystalline (α and γ) and amorphous Al2 O3 is measured by X‐ray photoemission. No significant changes are found in the different crystalline forms. A broad band observed at about 4 eV below the valence band is associated with the 2s states of the oxygen atoms, in agreement with band calculations. An electronic structure scheme of the aluminium oxide is constructed from photoemission, v. u. v. and X‐ray optical data.