The damage and healing of quartz under radiation at high temperatures

Abstract

The effect of radiation on silica has attracted significant attention due to its potential application where radiation exists. However, the nature of the atomistic defects of quartz formed during the radiation-induced damage at high temperatures has not been fully elucidated. Molecular dynamics is adopted to investigate the damage-healing behavior of the quartz at high temperatures in this research. The ensuing diffusion and recovery of point defects in the irradiated specimen at high temperatures are simulated. The high temperature reduces the number of point defects. At 1400 K, all point defects are removed, while only some point defects are erased at 700 K. It is illustrated that the over-coordinated atoms are the main source of point defects at 300 K and 700 K. The temperature influences the configuration of point defects. The healing variable of the molecular dynamics model is subsequently developed to describe the healing process. The healing mechanisms of the irradiated specimen at high temperatures are summarized by analyzing the trajectories of atoms in detail. These results are helpful to understand the nature of radiation damage in quartz at high temperatures.