Anisotropy in Oxidation of Zirconium Surfaces from Density Functional Theory Calculations

This work uses density functional theory calculations to analyze the energy barriers for oxygen migration into the basal and prismatic surfaces of zirconium. Specifically, the migration energy barriers between each octahedral site and tetrahedral site in the basal surface, prism surface, and the bulk are determined. The possible oxygen migration paths in each system are also analyzed. Oxygen has higher energy barriers to penetrating the basal surface than the prism surface. It also has a lower energy barrier to escape from basal surface than from the prism surface. This is consistent with the experimental observation that the prism plane of zirconium oxidizes more quickly than the basal plane