Oxygen adsorption on Zr(0001):: An ab initio study

The main goal of this paper is to study the oxygen adsorption on the Zr(0001) surface using first-principles total-energy calculations based on density-functional theory. We present preliminary results which concern the atomic oxygen adsorption on the Zr(0001) surface. We first report a static study where we calculate the atomic structure and adsorption energy for oxygen occupying various surface and subsurface sites at three different coverages: Theta = 1/4, 1/2, and 1 ML. We find that oxygen atoms are preferentially adsorbed into the octahedral holes between the 2nd and 3rd metallic layers. We secondly perform ab initio molecular dynamics calculations for the Zr(0001) - (3 x 3)- O system to show how the oxygen can penetrate through the surface and how it finally reaches its equilibrium position, trapped between the Ist and 2nd zirconium layers.