Summary: Electronic structure and bonding at the
Alterminated Al(111)/«Al2O3(0001) interface: A first principles study
Donald J. Siegel
Department of Physics, University of Illinois at Urbana-Champaign,
1110 West Green St., Urbana, IL, 61801.
Louis G. Hector, Jr.
GM Research and Development Center,
30500 Mound Road, P.O. Box 9055, Warren, MI 48090
James B. Adams
Chemical and Materials Engineering Department,
Arizona State University, Tempe, AZ 85287-6006.
We have performed ab initio calculations to determine the bonding character of the Alterminated
Al(111)/«Al2O3(0001) interface. By using an optimized model in which all atomic coordinates
were relaxed to their minimum energy positions, we have determined that AlO bonds constitute
the primary interfacial bonding interaction. Our electron localization, Mayer bond order, and Mul-
liken population analyses reveal that these bonds are very similar to the cationanion bonds found
in the bulk oxide, and are therefore mainly ionic, with a smaller amount of covalent character.
However, there is also evidence of metalcation bonding across the interface, a result which could
be significant to understanding bonding at interfaces with other corundum-like oxides.