Surface oxides on Al, Cu, Sn, Pb, and some of their alloys: an ESCA study

Abstract

The surface oxide structure of several metals and alloys has been examined by X-ray photoelectron spectroscopy (ESCA). The technique facilitates the measurement of oxide thickness, when less than ∼5 nm, such as Al2O3 on Al and SnO on Sn, by a combination of chemical shift and electron escape depth. The oxidation state of multivalent metals such as Cu, Pb, and Sn is determined by utilizing the chemical shift or the multiplicity of core states of excited ions. In addition ESCA is shown to be a potentially useful technique for studying bulk-to-surface diffusion phenomena in alloys.