Physical properties of predicted Ti₂CdN versus existing Ti₂CDC MAX phase: An ab initio study

Ab intio calculations were done to investigate the structural, elastic, electronic and optical properties of the Cd-containing theoretically predicted MAX phase, Ti₂CdN, in comparison with the isostructural and already synthesized phase, Ti₂CdC. These calculations reveal that the substitution of C by N affects the lattice parameter c, whereas the lattice parameter a, remains almost unchanged. All the elastic constants and moduli increase when carbon is replaced by nitrogen. The elastic anisotropy in Ti₂CdC is higher in comparison with that of Ti₂CdN. Both these nanolaminates are brittle in nature. The calculated electronic band structures and density of states suggest that the chemical bonding in these two ternary compounds is a combination of covalent, ionic and metallic in nature. Electrical conductivity of Ti₂CdC is found to be higher than that of Ti₂CdN. The calculated reflectivity spectra show that both the MAX phases Ti₂CdC and Ti₂CdN have the potential to be used as coating materials to minimize solar heating.