Modification of UO2 crystal morphologies through hydroxylation

Atomic scale computer simulation is used to predict the surface energies of UO2, subject to different hydroxide coverages. It was found that the {1 1 1} surface dominates dry UO2, resulting in an octahedral morphology. However, the {1 0 0} surfaces were strongly stabilized by hydroxylation relative to the {1 1 1} surfaces. Consequently, even a modest hydroxylation of 30% substantially truncates the octahedron crystal morphology, and a fully cubic morphology is predicted at 80% hydroxide coverage.