First-principles calculation of oxygen adsorption on Zr(0001) surface: Possible site occupation between the second and the third layer

Abstract

The oxygen adsorption on the Zr͑0001͒ surface is studied using first-principles total-energy and force calculations. We calculated the atomic structure, heat of adsorption, work function, and electronic structure for oxygen occupying various surface and subsurface sites for both the Zr͑0001͒-͑1ϫ1͒-O and Zr͑0001͒-͑2ϫ1͒-O system. We found that the energetically most favorable occupation sites for oxygen are the octahedral sites between the second and the third layer. The change in the work function induced by oxygen adsorption depends strongly on the position of the adsorbed oxygen atoms and the calculated change of work function at the energetically most favorable site is consistent with previous experiments. A large difference in the electronic structure between the overlayer and subsurface adsorption is also found. ͓S0163-1829͑96͒06743-4͔

Oxidation of Zircaloy-4 by oxygen and the production of water

“…Both theoretical [6,7] and experimental [8][9][10] studies indicate that subsurface adsorption (i.e. absorption) on zirconium dominates for oxygen at low exposures.…”

Photoemission study of the (2 × 2) structure formed by H2O adsorption on the Zr(0 0 0 1) surface

“…In the alternative model of the (2 · 2) structure presented by Wang et al, 0.25 ML of oxygen is adsorbed in the octahedral sites between the first and second metal layer and 0.25 ML between the second and third layer [7]. Using first principles calculations, Yamamoto et al [12] predicted that the octa- hedral adsorption sites between the second and third metal layer are energetically favourable sites to form (1 · 1) and (2 · 1) structures. Recently Jomard and Pasturel [13] suggested instead that the octahedral fcc adatom sites are the most favourable.…”

Adsorption of water on sulfur dioxide pre-exposed Zircaloy-4 surfaces

“…Even though the temperature is drastically reduced by the presence of sulfur, the desorption of H 2 O near 500 K from Zry-4 is unusually high when compared to desorption from other metal surfaces. 16,17 Both experimental 18 -20 and studies from the firstprinciples 21 of oxygen adsorption on zirconium indicate population of subsurface sites at low coverages. Therefore, desorption of water above 700 K when no sulfur is present most likely involves subsurface species.…”