Near-infrared study of radiation damage in ion-irradiated cerium dioxide and cerium-gadolinium dioxide

Costantini, J.-M.*; Guillaumet, M.*; Lelong, G.*; Ishikawa, Norito; Seo, P.*; Yasuda, Kazuhiro*

Nuclear Instruments and Methods in Physics Research B, 558, p.165567_1 - 165567_6, 2025/01

https://doi.org/10.1016/j.nimb.2024.165567

Radiation damage is studied in ion-irradiated sintered CeO and (Ce, Gd)O samples. Near Infra-red (NIR) spectra measurements were carried out by using the diffuse reflectivity mode for all of these sintered samples. Samples were irradiated with 100-MeV Kr, 200-MeV Xe, and 36-MeV W ions. Four broad absorption bands centered at 3700, 4100, 6000, and 7600 cm (i.e. 0.46, 0.51, 0.74, and 0.94 eV) are deduced from fits of the FTIR spectra for the ion-irradiated CeO and (Ce, Gd)O samples accompanied by a change in color from ivory to green. No such bands are recorded for the virgin (Ce, Gd)O samples with 5, 10, and 15 mol GdO with an increasing amount of oxygen vacancies. Absorption bands are tentatively assigned to electronic transitions involving cerium vacancy levels in the band gap, which has been also observed under high-energy electron irradiation.