Size dependent radiation-stability of ZnO and TiO ₂ particles

ZnO and TiO ₂ particles are typical pigments used in solar reflective coatings. In this letter, the radiation stability of ZnO and TiO ₂ particles within submicron (several hundred nm) and nanoscale (30 nm) size is systematically studied. We reported previously that the 90 nm and 300 nm ZnO particles have nearly a same radiation tolerance (Phys. Status Solidi B 2017, 254, 1600411). Unexpectedly, we found herein that the 30 nm oxides have significant higher radiation tolerance in relation to the submicron particles. Detailed analysis illustrated that the abundant native defects and surface/interface states in oxides nanocrystals, in-situ restored radiation damage through rapid diffusion and annihilation with implantation created vacancies. This work would be beneficial for developing nanoscaled oxides and devices used for space and nuclear radiative environments.