X-Ray photoelectron spectroscopy of iron–oxygen systems

X-Ray photoelectron spectroscopy has been used to study a series of iron oxides. It has been shown that iron metal has a different ionisation energy from a number of iron(III) oxides. Small perturbations to the energy of the iron (III) 2p electrons can be attributed to changes in crystal structure. Multiplet splitting and shake-up in the iron oxides contributes to iron 2p peak widths. The chemisorption of water has a marked effect upon the observed peak profiles; the oxygen 1s peaks due to oxide, hydroxyl, and adsorbed water have been characterised.