The Chemical Effect of Auger Spectrum in the Transition Metal Oxides and its Influence on the Relative Sensitivity Factor

Abstract

Auger spectra were investigated for both oxide and metallic states of some transition elements in order to obtain quantitative information about the composition and structure of thin oxide films formed on metals and alloys.
The peak shape for oxides was compared systematically with that for metals, and the effect of the change in the peak shape on the relative sensitivity factor by oxidation was discussed.
The oxides investigated were prepared by thermal oxidation of pure metals, ranging from Ti to Zn of the first row in the periodic table, and their Auger spectra in LMM transition were observed in a couple of modes as differential [dN⁄dE] and integral [N(E)]. It was shown that the spectra obtained exhibited a wide variety of width in the profile and of the relative intensities of their spectra of the LMM groups which involve valence band transitions depending on the oxidation state. But for the oxide states of Cu and Zn, the width change due to broadening was negligibly small. The relative sensitivity factors, based on pure metal, decreased for the oxide peak which exhibited broadening in the diffrential mode while in the integral mode it tended to increase. Though the shape of the oxygen spectra showed differences in minute detail, the width of the main peak was not changed considerably except for the case of ZnO.
The possibility of estimating the variation of the composition with depth and of determining the oxide/metal interface position from the AES data has been pointed out.