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 = 356 GPa, c₁₁ = 55 GPa, c₄₄ = 157 GPa. The bulk modulus B, shear modulus G and Young's modulus E are determined to be 156, 151 and 342 GPa, 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.