Role of structural ordering on the radiation response of Gd2Zr2O7 pyrochlore

Abstract

Complex oxides with pyrochlore and fluorite phases offer several advantages for the Immobilization of actinides or high-level radioactive wastes. In this report, we present the different behavior of structural ordering/crystallinity of Gd2Zr2O7 (GZO) ceramics upon sintering at two different temperatures (1400°C–1500 °C). XRD and Raman spectroscopy studies revealed the enhancement of structural ordering/crystallinity with the increase of sintering temperature. Further, the ion irradiation experiments using 100 MeV iodine at the fluence of 1.0 × 1014 ions/cm2 were performed to investigate the radiation effects on both GZO ceramics. The irradiation studies insinuate that the GZO ceramic sintered at 1500 °C possesses relatively better radiation resistance than GZO ceramic sintered at 1400 °C. The variation in the radiation resistance response of GZO ceramics seems associated with the different degrees of structural ordering. These results suggest the role of structural ordering in the radiation resistance response of GZO ceramics. The relatively better radiation tolerance of GZO15 ceramic with some extant pyrochlore phase ordering may be suitable for applications in harsh environments. © 2022 Elsevier Ltd and Techna Group S.r.l.