X-Ray Photoelectron Spectra of Aluminum Oxides: Structural Effects on the “Chemical Shift”

Abstract

The aluminum (2p) electron spectra of several anhydrous and “hydrous” aluminum oxides have been recorded, and the binding energies have been measured. A simple electrostatic model is employed to explain the observed shift in binding energy and relate it to differences in structure and hydrogen bonding. Two conclusions can be drawn: structural differences must be considered when interpreting photoelectron spectra for inorganic crystalline substances; and hydrogen bonding with anions may have a measurable effect on the binding energy of core electrons of the cations.

Reaction of Trimethylaluminum with Water on Pt(111) and Pd(111) from 10–5 to 10–1 Millibar

“…Kloprogge et al 43 41 Alexander et al 38 observed a shift of less than 1 eV to higher BE in the Al 2p peak centroid following heating of an AlO(OH) sample to 300°C in vacuum. Lindsay et al 44 measured Al 2p BEs of 76.3 ± 0.1, 74.8 ± 0.1, 75.7 ± 0.1, 74.9 ± 0.1, and 74.7 ± 0.2, for α-Al 2 O 3 , α-AlO(OH), β-AlO(OH), α-Al(OH) 3 , and β-Al(OH) 3 , respectively. The above references do not present a clear trend for aluminum oxides versus hydroxides, i.e., that oxide bound to aluminum results in a higher or lower Al 2p BE consistently versus hydroxide bound to aluminum.…”

A Practical Application of X-Ray Spectroscopy in Ti-Al-N and Cr-Al-N Thin Films

“…3(c) shows the Al2p3/2 spectrum. Four fitting peaks of the Al peak can be deconvoluted at 72.8 eV, 73.9 eV, 75.5 eV and 77.3 eV, moreover these peaks are associated to the Al-Al bond, Al-N, Al x O and Al 2 -O 3 with a single bond, respectively (Shum et al, 2003;Taylor & Rabalais, 1981;Lindsay et al, 1973). The XPS results demonstrate that Ti and the Al atoms have been bonded with N in the forms of nitride the elemental concentration of the Ti-Al-N film was controlled by adjusting the applied power of the Ti-Al binary target, and the Ar/N 2 g a s m i x t u r e .…”

“…5(c) shows the Al2p3/2 spectrum. Four fitting peaks of the Al peak can be deconvoluted in four peaks at 72.8 eV, 73.9 eV, 75.5 eV and 77.3 eV, moreover these peaks are associated to the Al-Al bond, Al-N, Al x -O and Al 2 O 3 with a single bond, respectively (Lindsay et al, 1973;Sanjinés et al, 2002;Briggs & Seah, 1994;Taylor, 1982;Kuo & Tsai, 2000;Barr, 1983;Endrino et al, 2007). The XPS results demonstrate that Cr and the Al atoms have been bonded with N in the forms of nitride.…”

A Study of the Adsorption of Ni(II) and Cu(II) by Clay Minerals

“…Measurements of the binding energies of aluminum in a variety of materials have revealed that binding energies are affected by stoichiometric changes in composition (Lindsay et al, 1973), but are not affected by alterations in coordination geometry (Anderson and Swartz, 1974). XPS studies of metal ions adsorbed on mineral surfaces have been valuable in describing the chemical nature of cobalt on metal oxides (Tewari and Lee, 1975) of iron on clay minerals (Koppelman and Dillard, 1975) and heavy metals on montmorillonite (Counts et al, 1973).…”