TEM Investigations of Ion-Irradiated Cerium Oxide Thin Film

Cerium oxide (CeO2) is of great interest due to its unique properties. The formation of a single oxygen-vacancy during the reduction of CeO2 to Ce2O3 increases the Ce3+ fraction [1,2,3]. The valence and defect structures of CeO2 are dynamic and can change spontaneously or in response to physical parameters such as temperature, partial oxygen pressure, doping with other ions, and on applying an electric field or surface stress. Nano-scale CeO2 particles possess an increased Ce3+ concentration in comparison to larger particles since the defect concentration is augmented at the surface. The simultaneous presence of Ce3+ and Ce4+ mixed valence states impart properties of ceria that have been deployed in various fields such as fuel cell materials, automotive catalysis, oxygen storage, and biological reactive oxygen species scavenging [4,5].