The temperature dependence of Cu2O formation on a Cu(110) surface with an energetic O2 molecular beam

We report a study of the surface temperature (T-s) dependence of Cu2O formation on a Cu(110) surface induced by a hyperthermal O-2 molecular beam (HOMB), using x-ray photoemission spectroscopy in conjunction with synchrotron radiation. From the T-s dependence of the O uptake curves, the direct dissociative adsorption process mainly contributes to the formation of the p(2 x 1)-O structure with an O coverage (Theta) of 0.5 ML for 2.2 eV HOMB incidence. On the other hand, the rate of oxidation at Theta > 0.5 ML, particularly in Cu2O formation, strongly depends on the T-s. Thicker Cu2O islands were found inhomogeneously at 400 and 500 K, suggesting the dominant role of the migration of Cu atoms in the Cu2O formations on the Cu(110) surface.