Evolution of Defective State of Aluminum Oxide Irradiated with Chromium Ions after Annealing in Oxygen Environment

Abstract

The characteristics of interband and exponential optical absorption of leucosapphire and polycrystalline corundum (polycor) after irradiation with chromium ions and subsequent annealing in vacuum at 300-1800 K and in air at 300-800 K are studied. Contributions of defects with different thermal and chemical stability into optical parameters were established. The effect of intrinsic radiation defects, of substitutional defects and of complexes on base of oxygen and defects on formation the focal point in absorption spectra owing to fulfilment of the Urbach rule was determined. Heating in air of strongly defective material synthesized in surface layers of alumina by the ion-heat modification influences the characteristics of defects and the electronic structure of band gap negligibly.