Effects of high-energy heavy ion irradiation on the crystal structure in CeO2 thin films

We studied the change in crystal structure of 200 MeV Xe and 10 MeV I ion irradiated CeO2 thin films by means of X-ray diffraction (XRD). The experimental result showed that the average lattice parameter of CeO2 decreased and the full width at half maximum increased by the ion irradiation. Their changes are well correlated with the electronic stopping powers for I and Xe ions. The dependence of lattice parameter on the electronic energy loss was analyzed by using the Poisson’s law, and the radii of the regions affected by the irradiation were determined.