The interaction of oxygen with the α-U(001) surface: an ab initio study

Abstract

First-principles calculations based on density functional theory have been performed to investigate the adsorption, dissociation and diffusion of oxygen on the α-Uranium(001) surface. The results showed that O2 tends to dissociate followed by the occupation of the two adjacent three-fold hollow sites. The weak molecular adsorption was found for O2 adsorbed perpendicularly at the top of a uranium (U) atom. The investigation of the dissociation for O2 from the top site with the O atoms falling into the two adjacent hollow sites indicated the spontaneous dissociation of O2. The surface diffusion of atomic oxygen between two adjacent hollow sites encountered an activation barrier of 0.55 eV, indicating the slow motion for O on the α-U(001) surface.