OXYGEN-ADSORPTION ON ALUMINUM SINGLE-CRYSTAL FACES STUDIES BY AES, XPS AND LEED

The adsorption of oxygen on low index single crystal faces of aluminum at room temperature has been studied by AES, XPS and LEED. In a combined AES and LEED investigation, AES data revealed that the (100) surface oxidizes in a manner different to that for the (110) and (111) surfaces which display similar oxygen uptake curves. The correlated LEED study presents another picture, since here it is rather the (111) surface which shows a separate behaviour. Independent XPS measurements confirm the uptake curves derived from AES data. By combining the AES, XPS and LEED results presented and geometrical considerations with recent photoemission and work function data and making the assumption that oxygen bonds ionically to the aluminum surface, we propose mechanisms accounting for the different behaviour of the crystal faces when exposed to oxygen. © 1979.