Radiation damage in ion-irradiated CeO2 and (Ce, Gd)O2 sinters: Effect of the Gd content

The radiation damage induced in cerium dioxide CeO2 and cerium-gadolinium mixed oxides (Ce, Gd)O2-x was studied by micro-Raman spectroscopy diffuse UV-visible reflectance spectroscopy. Sintered samples of undoped for 1 mol% 5 Gd2O3 were irradiated at room temperature with 2.5-MeV Ar2+ 12-MeV Ar4+ ions up to high fluences (i.e. × 1014 cm−2 2.1 respectively). Raman spectra show that no amorphization those occurs whatsoever, regardless the Gd content. No clear change cross section Gd3+ content is deduced from decay F2g peak intensity versus fluence. Moreover, reflectivity a decrease band-gap energy increase Urbach arising point defect accumulation. Similar effects are found Gd2O3, whereas larger effect on band tailing seen ceria. respective roles nuclear collisions electronic excitations discussed both ion energies knowing two kinds measurements do not probe same sample depth. substitution Ce4+ likely reducing formation tails related Ce3+ excitation processes.