X-ray photoelectron/Auger electron spectroscopic study of the initial oxidation of chromium metal

Abstract

Previous work on the oxidation of chromium is briefly reviewed and the theoretical aspects relating to the determination of surface concentrations of metal oxide films by X-ray photoelectron spectroscopy is discussed. An ultra-high vaccum, high resolution X-ray photoelectron/Auger electron spectrometer was used to observe the initial stages of oxidation of clean crystalline chromium following accurate redetermination of the binding energies of chromium core electrons and the work function of the clean metal. High resolution LMM Auger spectra have also been obtained from the clean metal for the first time and show fine structure not previously observed. Using both X-ray photoelectron spectroscopy and Auger electron spectroscopy the rate of formation of oxide films on the surface of the metal in low pressures of pure oxygen and under oxide ion bombardment has been investigated and limiting thicknesses of the films determined.