Characterization of the oxide/hydroxide surface of aluminium using x-ray photoelectron spectroscopy: a procedure for curve fitting the O 1s core level

Abstract

The performance of coated and bonded aluminium relies heavily upon its surface chemistry and hence characterization of the aluminium surface is important. A method to quantify the hydroxide concentration at aluminium oxide/hydroxide surfaces by curve fitting the O 1s peak is developed and tested in this paper.Pseudoboehmite, AlO(OH), is formed at the surface of aluminium after immersion in boiling water. The surface of this material was used to determine the binding energy of the unresolved O 1s component peaks that were referenced to the binding energy of the Al 2p oxide component. In vacuo heating resulted in changes in the elemental and functional composition that were consistent with dehydration of the pseudoboehmite. It is proposed that the resultant film comprises g-alumina with residual hydroxide groups.The O 1s curve-fitting method was applied to air-formed films with known atmospheric exposure histories before and after heating in vacuo. The change in both the elemental composition and functional stoichiometry of the films upon heating was consistent with significant but incomplete dehydration. The probable surface phases are determined from the functional and elemental composition.

XPS–SIMS Surface Characterization of Aluminovanadate Oxide Catalyst Precursors Co-Precipitated at Different pH: Effect of Calcination

“…The charge-corrected binding energies of the O1 component were found to vary non-monotonically in the range 531.5-532 eV for dried and 531.4-531.8 eV for calcined catalysts depending on precipitation pH. These values are larger than BE = 530.5 eV (our data, [25]) and 530.7 eV [26] measured for the O 2-component in the O 1s spectrum of corundum, but they are close to BE(O1-s) = 531.5 eV [27], 531.65 eV [28] [25][26][27][28]. These ranges are shown in Fig.…”

“…2a). In calcined V-Al-O, DBE(O1-Al) = 457.3-457.4 eV is practically independent of pH and is close to separations DBE(O-Al) in both gibbsite Al(OH) 3 [26] and boehmite AlOOH [26][27][28]. At pH [ 5.5, DBE(O1-Al) in calcined catalysts is somewhat lower than in dried samples indicating therefore some surface dehydroxylation.…”

“…As can be seen in Fig. 2a, all energy separations DBE(O1-Al) for the O1 component in V-Al-O are significantly larger than DBE(O-Al) in Al 2 O 3 but they fall in the region of the values DBE(OHAl) for hydrated species in trihydroxide Al(OH) 3 , being also close to DBE(O-Al) = 457.3 eV in boehmite AlOOH [26][27][28]. This means that aluminium on the surface of V-Al-O is largely bonded to hydroxyls (Al-O-H) and forms hydroxide/oxyhydroxide.…”

Valence band offset at Al2O3/In0.17Al0.83N interface formed by atomic layer deposition

“…It is highly likely that the O 1s I component corresponds to Al-O-Al bonds and the O 1s II component corresponds to Al-O-H bonds, which is in agreement with other reports. 6,7 In addition, the separation between O 1s I and the valence band maximum (VBM), E V , for the 16-nm-thick Al 2 O 3 layer was constant and independent of h, which indicates that this component can be used to determine the bulk constant parameter of the ALD Al 2 O 3 layer. Therefore, analysis of the band offset was carried out by using the O 1s I component.…”

Electric-field-induced magnetization changes in Co/Al2O3granular multilayers

“…O 1s peaks have been used for the calculation of relative proportions of different species in various materials and systems. [16][17][18][19] The experimental spectra is corrected by Shirley background and then fitted using a Voigt function. 18,20 The O 1s peak for Al-O bonding is at 531.6 eV, while the Co-O bonding peak is 530.4 eV for the fits.…”