Atomic relaxation of the BeO (1010) surface

Document Type

Article

Publication Date

6-1-1997

Abstract

The atomic relaxation of the nonpolar (1010) surface of BeO has been calculated by minimizing the surface energy within the framework of the ab initio Hartree-Fock method. A six-layer two-dimensionally periodic slab model was used, permitting a full symmetry-conserving relaxation of the two outer layers. The Be-O surface bonds show a small rotation angle of about 4° accompanied by a large (about 10%) reduction in surface bond length. Significant contraction of backbonds and a small rotation of second layer bonds are also found. The relaxed BeO (1010) surface is thus predicted to be similar to the ZnO (1010) surface but different from the corresponding surfaces of all other II-VI compounds. Various explanations for this difference are discussed, and evidence from a bond population analysis is presented which suggests that this behavior can be described in terms of partial double bond character in the surface bonds. Since multiple bonding is related to small atomic radii, it would follow that the small radius of the oxygen atom is the ultimate cause of the type of surface relaxation we predict. © 1997 Elsevier Science B.V.

Publication Title

Surface Science

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