Threshold Al KLL Auger spectra of oxidized aluminium foils

Abstract

Threshold Al KLL Auger electron spectroscopy and K-edge x-ray absorption fine structure spectroscopy have been used to examine technical purity (99.5%) aluminium foil before and after chemical treatment that altered the thickness and degree of hydroxylation of the oxidized layer. Comprehensive surface chemical characterization was effected by means of monochromatized Al Ka-excited photoelectron spectroscopy. Threshold Al KL 2,3 L 2,3 spectra were obtained for three of the foils investigated and these spectra were in broad agreement with those observed previously for pure Al foil. The relative intensities of the spectral components for two of the foils were clearly consistent with the previously proposed assignment of the resonantly enhanced Auger component, situated between those arising from the metal and Al(III) oxide, to a thin interfacial layer. The threshold Auger spectra from the aluminium foil bearing the thickest and most hydroxylated oxidized layer were not obviously consistent with the interfacial layer model but O K-edge spectra revealed that this surface layer was fundamentally different from the others and could have had a greater interfacial surface area.

Theoretical Investigation of Al K-edge X-ray Absorption Spectra of Al, AlN and Al<SUB>2</SUB>O<SUB>3</SUB>

“…However, our firstprinciples results for pure metallic Al agreed well with the experimental data, although the present experimental line shapes showed spectral features similar to those described in the previous report. 17) From the results of our present calculations, it is concluded that the main component of the present Al K-edge spectrum of metallic Al measured by the TEY method was bulk metallic Al. In the case of AlN, peak E was missing in the theoretical spectra obtained with the 3 Â 3 Â 1 supercell, although this supercell provided better agreement with the experimental data than the smaller 2 Â 2 Â 1 supercell.…”

“…In the case of metallic Al, the agreement between the experimental and calculated spectral profiles was slightly improved by increasing the supercell size. The previous report 17) mentioned that the XANES profile of metallic Al mainly originated from Al oxides and/ or hydroxides when it was measured by the TEY method, which was the main reason why the spectral profiles differed between the TEY and TFY methods. However, our firstprinciples results for pure metallic Al agreed well with the experimental data, although the present experimental line shapes showed spectral features similar to those described in the previous report.…”

“…15,16) Various Al K-edge XANES spectra of Al compounds have been extensively studied both experimentally and theoretically. A high-resolution experimental Al K-edge XANES spectrum of metallic Al was obtained 17) using the total electron yield (TEY) and the total fluorescence yield (TFY) methods for the measurements. It was reported that differences in the spectral fine structures were observed between TEY and TFY, but no theoretical interpretation was presented.…”

“…It was reported that differences in the spectral fine structures were observed between TEY and TFY, but no theoretical interpretation was presented. 17) Experimental XANES spectra of AlN were reported, 16) and the experimental fine structure was quantitatively explained by using the OLCAO method. Mention was made in that report of a striking core-hole effect on the theoretical estimation of the XANES/ELNES spectra.…”

A combinatorial comparison of DC and high power impulse magnetron sputtered Cr2AlC

“…(peak f), ~1566 eV (peak g) and ~1568 eV (peak h) originate from aluminium bonded to oxygen in either a disordered octahedral (peaks f and h) or tetrahedral (peak g) arrangement [36,37]. The peak located at 1571 eV (peak i) is due to multiple scattering events [38].…”