A Density Functional Study of Oxygen Adsorption on the ThN {100}, {110} and {111}

Abstract

Thorium nitride (ThN) is a promising metallic nuclear fuel with substantially higher actinide density and higher thermal conductivity that are currently being investigated as a candidate nuclear fuel for Generation-IV reactors. However, the oxidation of the metallic fuel is a major challenge that needs to be addressed before considering its commercialapplication. Therefore, in this study, we employ the use of density functional theory calculations to investigate the effect of adsorption of oxygen on the {100}, {110} and {111} surfaces of ThN. The surface energies and the adsorption energies of all the surfaces considered were calculated, and a comparison of the surface energies of the oxygen adsorbed ThN systems with that of the clean ThN surfaces was made. The surface energies of the {100}, {110} and {111} surfaces were calculated to be 1.102 1.53, 1.672 J/m2 respectively, indicating {100} surfaces to be the most stable surface.