Investigation of multiplet splitting of Fe 2p XPS spectra and bonding in iron compounds

Abstract

Abstract Ferrous (Fe 2+ ) and ferric (Fe 3+ ) compounds were investigated by XPS to determine the usefulness of calculated multiplet peaks to fit high‐resolution iron 2p 3/2 spectra from high‐spin compounds. The multiplets were found to fit most spectra well, particularly when contributions attributed to surface peaks and shake‐up satellites were included. This information was useful for fitting of the complex Fe 2p 3/2 spectra for Fe 3 O 4 where both Fe 2+ and Fe 3+ species are present. It was found that as the ionic bond character of the iron —ligand bond increased, the binding energy associated with either the ferrous or ferric 2p 3/2 photoelectron peak also increased. This was determined to be due to the decrease in shielding of the iron cation by the more increasingly electronegative