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 °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 °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 °C) results in the same near‐surface O concentration profile as the 250 °C exposure.