Atomic structure of diamond {111} surfaces etched in oxygen water vapor

The atomic structure of the {111} diamond face after oxygen--water-vapor etching is determined using x-ray scattering. We find that a single dangling bond diamond {111} surface model, terminated by a full monolayer of ---OH fits our data best. To explain the measurements it is necessary to add an ordered water layer on top of the ---OH terminated surface. The vertical contraction of the surface cell and the distance between the oxygen atoms are generally in agreement with model calculations and results on similar systems. The OH termination is likely to be present during etching as well. This model experimentally confirms the atomic-scale mechanism we proposed previously for this etching system.