First-principles study on phase stability and compression behavior of Ti2SC and Ti2AlC

We have performed first-principles study on phase stability and compression behavior of Ti2SC and Ti2AlC. Ti2SC is found to be more stable than Ti2AlC due to its deeper pseudogap, lower density of states at the Fermi level and stronger Ti d–S p hybridization. Ti2SC shows higher stiffness than Ti2AlC when compressed. The calculated bulk modulus is 181 and 162 GPa for Ti2SC and Ti2AlC, respectively. The bond strength of Ti2SC and Ti2AlC becomes greater at high pressures. However, no evidence for any change in the nature of the bonding under pressure is observed.