Helium irradiation effects on MgO-Nd2Zr2O7 composite ceramics prepared by one-step method used for inert matrix fuel

In this work, the helium irradiation effects were systematically investigated on MgO-Nd 2 Zr 2 O 7 (hereafter M-NZO) composite ceramics used for inert matrix fuel, in which the ion fluences range from 5 × 10 16 to 3 × 10 17 ions/cm 2 at room temperature. It was demonstrated that M-NZO composite ceramic shows superior radiation tolerance after He implantation. Specifically, MgO had almost no phase transition and extensive amorphization . And Nd 2 Zr 2 O 7 phase possessed slightly pyrochlore-fluorite-amorphization structural transformation, while part of Nd 2 Zr 2 O 7 maintained the ordered pyrochlore structure and co-existed with the irradiation-induced disordered fluorite structure. Importantly, GIXRD results indicated that MgO phase presents higher resistance to radiated damage than Nd 2 Zr 2 O 7 phase. Besides, SEM images illustrated that MgO particles have substantially less fragmentation than Nd 2 Zr 2 O 7 particles due to the higher thermal conductivity of MgO. It reconfirmed that MgO phase resists irradiation damage better than Nd 2 Zr 2 O 7 phase in post-irradiated M-NZO composite ceramics.