A Simulation Study on Irradiation Damage of Rutile TiO2

Abstract

In this study, threshold displacement energy of O and Ti in rutile TiO2 along different directions is simulated by using the method of molecular dynamics. Simulation results show that threshold displacement energy of O atom in all directions is generally lower than that of Ti atom. The threshold displacement energy of O is basically between 27.50 and 77.50 eV, while that of Ti is between 90.00 and 120.00 eV. Meanwhile, this study also explores the cascade radiation damage caused by O PKA and Ti PKA with energy of 1.0, 5.0 and 10.0 keV. Cascade radiation damage results show that O PKA and Ti PKA with energy less than 10.0 keV mainly produced point defects. The number of point defects reached the peak within 0.10 ~ 0.20 ps. After several ps evolution, more than 90.0% of the defects are annealing, and only less than 10.0% defects remained. In other words, the defects in rutile TiO2 have higher self-recovery ability at the initial stage of defect generation.