Summary: Adhesion, Atomic Structure, and Bonding at the «Al2O3(0001)/Al(111) Interface:
A First Principles Study
Donald J. SiegelÝ
Department of Physics, University of Illinois at Urbana-Champaign,
1110 West Green St., Urbana, IL, 61801.
Louis G. Hector, Jr.
Surface Technology Division, ALCOA Technical Center - C,
100 Technical Dr., ALCOA Center, PA 15069-0001.
James B. AdamsŢ
Chemical and Materials Engineering Department, Arizona State University,
Tempe, AZ 85287-6006.
(Dated: December 3, 2000)
We have performed a series of ab initio calculations to determine the atomic structure, ideal work of adhe-
sion (Ď ), and bond character of the «Al2O3(0001)/Al(111) interface. A total of six candidate interface
structures were considered, taking into account both Al and Oterminations of the oxide. Minimization
of the Hellman-Feynman forces resulted in large local changes in the crystal structure of the metal atoms
near the interface, in which some atoms from the metal slab adopt positions consistent with a continua-
tion of the oxide's Al-sublattice crystal structure across the interface and into the metal. Consequently,
we find that the lowest energy structures (i.e., having the largest Ď ) are those that facilitate this "oxide
extension" mechanism. By applying several methods of analysis we have thoroughly characterized the