Kinetics and mechanism of the oxidation of cerium in air at ambient temperature

•XRD and transverse sections suggest Ce2O3 forms on Ce before being overlaid by CeO2.•XRD and oxide thickness measurements both indicate linear oxidation.•Extensive cracking on oxide surface which sustains continuing oxidation.•Electron microscopy has shown features indicative of nodular oxidation.•Oxide growth rate determined to be 0.1 μm day−1 under the conditions in this study.

This paper describes a study of the oxidation of cerium in air at ambient temperature. Specimens were exposed for up to 60 days, during which they were analysed by X-ray diffraction (XRD) at regular intervals. Both XRD and oxide thickness measurements indicate linear oxidation over the duration of this study. Under the conditions employed in this study, the rate of oxide growth has been determined to be 0.1 μm day−1. The oxidation process appears to be assisted by extensive cracking in the oxide layer which acts as a non-protective film for the underlying metal.