Electronic structure of α-Al2O3
Abstract
The author has calculated the electronic energy structure of alpha -alumina in corundum structure ( alpha -Al2O3) using a first principles extended tight-binding method. The interest in the electronic properties of alpha -Al2O3 is expanding because of well-documented interest in chemisorption of oxygen on aluminium and the oxidation of aluminium itself. To understand bonding in this compound the author has compared his results with the known electronic structure of alpha -quartz ( alpha -SiO2). The latter has been investigated much more thoroughly and has similar properties to alpha -Al2O3. The authors have noted certain trends in going from alpha -Al2O3 to alpha -SiO2. These trends are quite similar to those reported in a cluster model calculation on AlO4 and SiO4. The author has also calculated the total and orbital densities of states and have compared these with X-ray photoemission spectra. It has been found that the calculated results do not agree fully with the existing experimental data. The author also briefly comments on the controversial O-Al bond length for oxygen chemisorbed on Al(111).