Simulated self-irradiation effects of Gd2Ce2O7 nuclear waste form.

To simulate self-irradiation effects of nuclear waste forms in long period of deep geological disposal, Gd2Ce2O7 as simulated An4+ matrix was chosen to be irradiated using 0.5 MeV alpha ions to fluences ranging from 1 × 1015 to 1 × 1017 ions cm−2. Irradiation-induced structural change and microstructural evolution were examined using grazing incidence X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Lattice swelling and amorphization in irradiated layer indicated an enhanced disordering degree with increased ion fluences. Main Raman peaks broaden and intensity decrease indicated a significant bonds distortion. In addition, no element aggregation about Gd, Ce and O occurs after He2+ irradiation. [ABSTRACT FROM AUTHOR]