Photoelectron spectroscopic study of the interaction of nickel and oxygen

Abstract
The adsorption of oxygen on nickel foils is characterized by two kinetic regions. In the first (coverage, ≲ 0.4 monolayers) it is established that chemisorption occurs with little consequent change in the core and valence spectra which indicates that the surface metal atoms retain their metallic character. In the range 0.5 ≲θ≲ 2.0 the core and valence level spectra reflect the occurrence of oxide nucleation and finally the formation of a passive film of NiO.