Photoemission study of the translational energy induced oxidation processes on Cu(111)

The oxidation processes of Cu(111) with a hyperthermal O(2) molecular beam (HOMB) were studied using high-resolution x-ray photoemission spectroscopy in conjunction with a synchrotron radiation source. The O-uptake curves were precisely measured at similar to300 K when irradiating with 2.3 and 0.6 eV HOMB on a Cu(111) surface. A Langmuir-type adsorption model at an oxygen coverage (Theta)less than or equal to0.4 ML describes the kinetics of dissociative adsorption in the HOMB incidence. On the other hand, further inefficient oxidation occurs even for the 2.3 eV HOMB irradiation at Thetagreater than or equal to0.4 ML. A collision-induced absorption mechanism can interpret the slow oxidation process of Cu(111). (C) 2004 American Vacuum Society.