The influence of surface defects on the [formula omitted] interaction

Abstract

Auger electron spectroscopy (AES) and angle-resolved secondary ion mass spectrometry (ARSIMS) have been used to examine how surface defects influence the oxygen adsorption and oxidation process on Al(100). The influence of surface defects was investigated by comparing results obtained for two Al(100) surfaces that were subjected to different surface polishing procedures which produced substantially different concentrations of defects on the two surfaces. Surface defects are shown to dramatically increase the rate of oxygen adsorption, strongly facilitate penetration of oxygen into the subsurface, enhance subsurface oxidation and reduce the exposure required for the onset of oxide formation. Interestingly, it is also shown that once oxidation begins, the enhanced rate of oxygen adsorption caused by defects does not significantly alter the rate of oxidation of the near-surface region, but instead contributes primarily to enhanced penetration of oxygen into the subsurface and subsurface oxidation.