Interplay between theory and experiment in the quest for silica with reduced dimensionality grown on a Mo(1 1 2) surface

The stability of ordered one- and two-dimensional silica structures formed on a Mo(1 1 2) surface as a function of silicon coverage and oxygen pressure (phase diagram) is derived from density functional theory. At elevated oxygen pressures formation of a new, previously not considered structure of two-dimensional silica film is predicted. It contains additional oxygen atoms adsorbed directly on the Mo(1 1 2) surface underneath a two-dimensional network of corner sharing [SiO4] tetrahedra. The existence of the new phase is confirmed experimentally using infrared reflection absorption spectroscopy and X-ray photoelectron spectroscopy.