Mechanisms of the structure evolution in irradiated silica glass: A view from molecular dynamics simulations

Abstract Silica glass has been widely used in the field of aerospace due to its excellent optical properties and high irradiation resistance. However, defects can still accumulate after excessive irradiation, resulting in the decrease of material properties thus possible device damage. At present, the microscopic mechanisms of the defect formation and structure evolution in silica glass after irradiation are still far from fully understood. The results show that the energy induced by irradiation can lead to a ballistic effect, which will cause atomic displacement and break the inter‐atomic bonds. In addition, a large area of porous space can be another type of radiation product, and the area of the porous space rapidly grows to the maximum and then gradually reduces. The ring structures get reformed and defect structures partially recombine with each other during the structural relaxation. However, the residual damage still exists, which contributes to the optical property change in experiments. These results provide useful insights into the atomistic mechanisms of the defect formation and structure evolution of silica glass under irradiation, they can also benefit the future design of optical devices under an irradiation environment.