Displacement cascade simulation of LiAlO2 using molecular dynamics

To elucidate the radiation damage process on an atomic scale, displacement cascade simulations of LiAlO2 were performed using molecular dynamics. Results of simulations obtained when an oxygen atom as the primary knock-on atom was displaced with the energy of 1-5 keV showed that the correlation between migration barriers of point defects and the declining rate of the maximum kinetic energy of atom in the system determined the thermal spike duration. The thermal spike of each element might finish when the maximum kinetic energy among all atoms of each element diminishes at around the point defects' migration barrier. Defect-cluster analysis revealed that vacancies produce larger clusters than interstitials do, perhaps because the strong Coulomb interaction in ionic materials renders interstitials resistant to aggregation.