Radiation damage in cubic ZrO2 and yttria-stabilized zirconia from molecular dynamics simulations

We perform molecular dynamics simulation on cubic ZrO2 and yttria-stabilized zirconia (YSZ) to elucidate defect cluster formation resulting from radiation damage and evaluate the impact of Y dopants. Interstitial clusters composed of split-interstitial building blocks, i.e. Zr-Zr or Y-Zr were formed. Oxygen vacancies control cation defect migration; in their presence, Zr interstitials aggregate to form split interstitials, whereas in their absence Zr interstitials remain immobile, as isolated single-interstitials. Y-doping prevents interstitial cluster formation due to sequestration of oxygen vacancies.