ORDERING OF FRACTIONAL MONOLAYERS OF H2O ON NI(110)

The ordering of water adsorbed on Ni(110) at monolayer and lower coverages was studied using molecular dynamics simulations. No long-range order could be found for the complete monolayer. At fractional coverage of theta approximately 0.9, oriented zones of quasi-hexagonal ice-like structure are stabilized by the formation of empty gaps aligned along the [001] direction. At half coverage we observed the aggregation of hydrogen bonded patches. The growth process is dependent on the highly anistropic surface diffusion with the faster rate in the less dense [110] direction. These results have been obtained using a novel model for the water-substrate interaction, treating the site specific chemisorption and electrostatic induction in atomic detail.