Step-by-step mechanism of oxygen interaction with metals

The results are reported of the study of the initial stages of interaction of low-pressure oxygen with Nb, W, Mo and Ni by means of the mass-spectrometric and secondary ion-ion emission methods. The results tend to indicate that the initial stages of the process occur in W and Mo in a manner different from that in Ni. In the former two metals, the initial stage of the process under consideration involves the accumulation of atomic oxygen on the surface of the metal which then leads to the appearance of two-dimensional oxides in the surface layer, whereas in nickel the first step is the adsorption of oxygen atoms by the metal, and the surface oxides are formed without the adsorption of oxygen atoms. The subsequent states are qualitatively the same both in W and W, on the one hand, and in Ni, on the other hand