ON A MECHANISM OF SURFACE OXIDE FORMATION NEAR THE NUCLEATION THRESHOLD

A kinetic theory of submonolayer oxide formation on solid surfaces near the transition point from adsorption to surface oxide growth has been developed. The theory is based on vacancy instabilities of surface layers interacting with oxygen. The driving force onset of the surface oxidation is shown to be spontaneous vacancy generation when the oxygen coverage approaches the critical value. This gives rise to a substantial decrease of the critical radius for oxide islands and consequently to simultaneous oxide phase nucleation.