Electronic Structure and Elastic Properties of Ti₃AlC from First-Principles Calculations

We perform a first-principles study on the electronic structure and elastic properties of Ti₃AlC with an antiperovskite structure. The absence of band gap at the Fermi level and the finite value of the density of states at the Fermi energy reveal the metallic behavior of this compound. The elastic constants of Ti₃AlC are derived yielding c₁₁=356GPa, c₁₂=55GPa, c₄₄=157GPa. The bulk modulus B, shear modulus G and Young's modulus E are determined to be 156, 151 and 342GPa, respectively. These properties are compared with those of Ti₃AlC₂ and Ti₂AlC with a layered structure in the Ti-Al-C system and Fe₃AlC with the same antiperovskite structure.