| Abstract
| - Adsorption of water on a thin silica film grown on a Mo(112) single crystal was studied by temperature-programmed desorption, infrared reflection absorption spectroscopy, and photoelectron spectroscopy usingsynchrotron radiation. Water does not dissociate on the defect-free oxygen-terminated silica surface. In contrastto adsorption at 100 K, where water follows a zero-order desorption kinetics, water adsorbed at 140 K exhibitsa pseudo-first-order kinetics and induces a strong blue shift of the silica phonon. Even larger spectral changeswere observed for D2O adsorption. The results were rationalized in terms of the formation of an amorphoussolid water film at 100 K and a crystalline ice monolayer film at 140−150 K. This film is well-ordered asrevealed by low-energy electron diffraction showing a c(2 × 2) superstructure with respect to the silica substrate.
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