Abstract
Structural stability, adhesion, and chemical bonding of the (0001) and (0001) interfaces are investigated by an ab initio approach based on density functional theory. The interfaces are shown to have different stable structures of , Al, or O termination depending on the chemical potential of aluminum or oxygen atom. A link to thermodynamic factors, i.e., the partial pressure of oxygen gas or the activity of aluminum, is established based on the ab initio thermodynamics developed recently. For condition applicable to sessile drop experiments, the O-terminated interface could exist for the system but be hard to observe for the interfaces, consistent with the known experiments. The termination is possible for the interface at relatively low pressure or high Al activity but may be hard to form for the interface. Works of adhesion of the stoichiometric interfaces are calculated to be in generalized gradient approximation (GGA) and in local density approximation (LDA) for the interface, in GGA and in LDA for the interface, in reasonable agreement with measured data.
1 More- Received 18 April 2005
DOI:https://doi.org/10.1103/PhysRevB.72.115423
©2005 American Physical Society