Surface structure of zinc oxide ( [formula omitted]), using an atomistic, semi-infinite treatment

• Published in: Surface science Vol. 498; no. 1; pp. 135 - 146
• Main Authors: Whitmore, Lee, Sokol, Alexey A., Catlow, C.Richard A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.2002; Amsterdam Elsevier Science; New York, NY
• Subjects: Computer simulations; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Single crystal surfaces; Solid surfaces and solid-solid interfaces; Surface defects; Surface relaxation and reconstruction; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Zinc oxide; Zinc oxide; Single crystal surfaces; Surface relaxation and reconstruction; Computer simulations; Surface defects; Crystal defects; Inorganic compounds; Theoretical study; Transition elements Compounds; Computerized simulation; Surface topography; Structure relaxation; Surface structure; Interatomic potential; Surface reconstruction; Zinc oxides; Surface defect; Crystal faces
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(01)01588-6

The surface structure of zinc oxide (1 0 1 ̄ 0) has been investigated computationally using new atomistic potentials in an effort to rationalise results of previous experimental and theoretical studies. We find that the uppermost zinc atoms have a significant relaxation towards the bulk (0.25 Å) but the zinc atoms in the second layer show a significant relaxation away from the bulk (0.165 Å), allowing them to appear as surface atoms. In agreement with recent ab initio results, only small relaxation is found for surface oxygen atoms. Our results suggest a high and variable concentration of dimer defects in both layers one and two, where the energetic cost for defect formation is very low, which promotes the likelihood of two-layer defects, consistent with the observed two-layer step height. The bulk termination is also subject to high concentrations of dimer vacancies which corresponds to recent findings of fractional occupations in the surface layers by Jedrecy et al. [Surf. Sci. 460 (2000) 136].