Layered Structure Induced Anisotropic Low-Energy Recoils in Ti3SiC2

Low‐energy recoil events in Ti3SiC2 are studied using ab initio molecular dynamics simulations. We find that the threshold displacement energies are orientation dependent because of anisotropic structural and/or bonding characteristic. For Ti and Si in the Ti–Si layer with weak bonds that have mixed covalent, ionic, and metallic characteristic, the threshold displacement energies for recoils perpendicular to the basal planes are larger than those parallel to the basal planes, which is an obvious layered‐structure‐related behavior. The calculated minimum threshold displacement energies are 7 eV for the C recoil along the [0001¯] direction, 26 eV for the Si recoil along the [21¯1¯0] direction, 24 eV for the Ti in the Ti–C layer along the [21¯1¯0] direction and 23 eV for the Ti in the Ti–Si layer along the [21¯1¯0] direction. These results will advance the understanding of the cascade processes of Ti3SiC2 under irradiation and are expected to yield new perspective on the MAX phase family that includes more than 100 compounds.