NONDESTRUCTIVE DEPTH PROFILE STUDY OF OXYGEN-EXPOSED LARGE-GRAIN SILVER USING ANGLE-RESOLVED AUGER-ELECTRON SPECTROSCOPY AND ION-SCATTERING SPECTROSCOPY

The adsorption of oxygen on polycrystalline Ag during exposure to 75 Torr of O2 for 1 h at temperatures ranging from 75 to 250-degrees-C has been examined using ion scattering spectroscopy (ISS) and angle-resolved Auger electron spectroscopy (ARAES). Quantification of these data provide the profile of the O concentration in the near-surface region of the Ag as a function of exposure temperature. The O concentration in the outermost atomic layer increases from 0% according to forward-scattered ISS for the cleaned surface to a maximum value of about 50 at.% for the 250-degrees-C exposure. A very small amount of subsurface O remains on the cleaned Ag surface after prolonged ion sputtering and annealing treatments. The total amount of subsurface O also increases monotonically with dosing temperature and reaches a uniform concentration level of 14 at.% over the region probed by Auger electron spectroscopy (AES). Exposures at higher temperatures (up to 600-degrees-C) results in the same near-surface O concentration profile as the 250-degrees-C exposure.