Unravelling the threshold displacement energy of TaC using ab initio molecular dynamics simulation

The threshold displacement energy (Ed) determines the quantity of defects generated through the minimum kinetic energy of a particle. Here, the displacement process of TaC is studied and hence the Ed is determined utilizing the ab-initio molecular dynamics simulation method. We use seven different crystallographic orientations, namely [100], [110], [111], [210], [211], [221], and [321] to observe the interaction between the primary knock-on atoms (PKAs) for both Ta and C. The computation of Ed values is taken between 16 eV and 50 eV. The weighted average Ed values are calculated from PKA orientations, which are found to be 42 eV for the Ta atom and 26 eV for the C atom. For Ta PKAs, anti-site defects are developed; however, they are not observed in the case of C PKAs. The collision mechanism is primarily influenced by the consecutive replacement collisions occurring along the [110] atomic row, resulting in a reduction of the Ed value in the crystallographic orientations. Finally, it is found that the Ed values play the role of creating the interstitial defects in the TaC.