Molecular dynamics simulations of cascade events in AlN

Abstract

The radiation tolerance and the ability to retain its piezoelectric response make aluminum nitride (AlN) a good candidate for emerging sensing technologies in nuclear reactor environments. Furthermore, it has been shown that doping the ceramic with additional metals can further improve the piezoelectric response. Fundamental understanding of the response of AlN to radiation is important for ultimately improving the material's properties. In this paper, we use molecular dynamics and a recently developed interatomic potential fitted to defect energies to investigate low energy collision cascades in AlN. We additionally investigate the electronic stopping effect in the damage production for 20 keV Al ions. Our results show that for all energies the number of Al surviving defects is larger than that of N defects. Additionally, we find that even though the ballistic energy loss is the dominating mechanism, it is important to take into account the electronic stopping in order not to overestimate the number of defects.