XPS, FTIR, EDX, and XRD analysis of Al₂O₃ scales grown on PM2000 alloy

This work is an original example to compare the results obtained after calcination of Al<inf>2</inf>O<inf>3</inf> hydroxides and oxidation of alumino-formers alloys. FTIR and XPS signatures were obtained for various oxidation temperatures and compared with those known from the literature about calcination of Al<inf>2</inf>O<inf>3</inf> precursors. The aim of this work is to evaluate the use of IR spectroscopy and XPS analysis to probe the structural varieties of Al<inf>2</inf>O<inf>3</inf>. For this objective, a study of the PM2000 oxidation at various temperatures was conducted by means of XRD, IR spectroscopy, XPS analysis, EDX analysis, and SEM observations. This allowed us to clearly differentiate the transition Al<inf>2</inf>O<inf>3</inf> from the α-Al<inf>2</inf>O<inf>3</inf> and, amongst the transition Al<inf>2</inf>O<inf>3</inf>, to differentiate the characteristic of the IR spectrum of γ-δ phases from that of the θ phase.