Determining the threshold displacement energy of magnesium using molecular dynamics simulations

Despite its potential use as a lightweight material, the effects of irradiation on magnesium (Mg) remain poorly understood. Specifically, the threshold displacement energy (TDE), which corresponds to the minimum energy required to displace an atom from the lattice position has not been explored so far. Here, using molecular simulations, we estimate the TDE of an Mg single crystal. We observe that the TDE is not significantly affected by the location of an atom in the lattice and the incident direction of energy or collision. We also demonstrate the formation of local defects, which are instantly annealed. Interestingly, the annealing process is facilitated by the temporary displacement of atoms from their lattice position into the interstitials, which in turn results in the creation of at least one stable Frenkel pair defect. Overall, this study provides insights into the response of Mg crystal to radiation, which is crucial for development of Mg-based structures for applications in aerospace and nuclear industries. (author)