First-principles study on structural, electronic and elastic properties of graphene-like hexagonal Ti2C monolayer

• The second-order elastic constant c11 and c12 of 2D Ti2C are 137 N/m and 32 N/m.
• The in-plane Young’s modulus and Poisson’s ratio of 2D Ti2C are 130 N/m and 0.23.
• 2D Ti2C is less stiffer than graphene and 2D h-BN.
• Elastic properties of 2D Ti2C are comparable to 2D MoS2.
• 2D Ti2C shows a higher N(EF) due to the redistribution of Ti 3d electrons.

We performed first-principles calculations on the structural, electronic and elastic properties of graphene-like hexagonal Ti2C monolayer. Compared with the Ti2C slab in Ti2AlC, the free-standing Ti2C monolayer slightly shrinks in all directions. Ti2C monolayer exhibits a higher value of density of states at Fermi level than Ti2AlC, due to the redistribution of Ti 3d electrons near the Fermi level after the removal of Al layers from Ti2AlC. The elastic constant c11 and c12, in-plane Young’s modulus Ys, and Poisson’s ratio v of Ti2C monolayer are found to be 137 N/m, 32 N/m, 130 N/m and 0.23, respectively. The elastic properties of Ti2C monolayer were compared with some other two-dimensional layered materials.