Journal of the American Ceramic Society · 1988 · 12 citations · 10 references
Natural SciencesChemistryMaterials ScienceMaterials ChemistrySurface ChemistrySurface SciencePhotoelectron SpectroscopySurface AdsorptionSurface Chemistry Of SolidsSurface OxidationSurface PhysicsX-ray Photoelectron SpectroscopyAdsorbate CharacterizationAdsorption On Oxide SurfacesAdsorption On OxidesAngle-resolved Photoelectron SpectroscopyAngle-resolved X-ray Photoelectron SpectroscopyPotassium AdsorptionSurface Chemistry Of SilicaSurface Oxidation States
The adsorption of potassium onto a clean silica surface has been studied by X‐ray photoelectron spectroscopy (XPS). The fracture surface of silica was cleaned by Ar + sputtering and exposed to potassium metal vapor for 10‐s intervals up to 50 s, resulting in 0.2 to 2 monolayer coverage. High‐resolution XPS spectra were recorded for the K 2p, O 1s, and Si 2p photoelectrons at each potassium exposure. Potassium uptake curves were generated from peak areas which suggest the mechanism of adsorption. Curve synthesis techniques were employed on the O 1s spectra to identify the various chemical states present. A decrease in a reactive state is observed as the number of nonbridging oxygen states increases. Angleresolved XPS was also used to determine the relative position, with respect to depth, of these reactive sites, showing that they are at a higher concentration near the surface.
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