Photoelectron spectroscopy study of interaction of oxygen with the (111) surface of a Cu–Zn alloy

Interaction of O atoms with the (111) surface of a Cu–Zn alloy with a face-centered cubic structure (α-brass) is investigated by photoelectron spectroscopy utilizing synchrotron radiation. The O adatoms interact mainly with the Zn atoms to form the ZnO islands, whereas the CuO bond formation is negligible in the initial oxidation stages at room temperature. O adsorption induces a binding-energy shift of the Shockley-type surface states towards the Fermi level. Also induced is a lowering of the work function of the α-brass(111) surface. These O-induced changes resemble those on the alkali-metal-covered Cu (111) surface. Similarity between Zn on the brass surface and alkali metals adsorbed on Cu (111) in initial oxidation is discussed.