First-principles study of the structural, electronic and elastic properties of ternary Zr2AN (AÂ =Â Ga, In and Tl)

The structural, electronic and elastic properties of ternary Zr2AN (A = Ga, In and Tl) ceramics have been studied by first-principles calculations. The obtained lattice parameters are in agreement with available data. The computed lattice parameters increase with increasing the atomic radii for A elements, whereas the cohesive energies and Debye temperatures decrease accordingly. The band structure shows that these three ceramics are all conductive. The density of states at the Fermi level (Ef) mainly originates from Zr d state with a minor contribution of A p states. Below Ef, the hybridization peak of Zr d-N p lies in lower energy range which indicates that Zr-N bond is stronger than Zr-A bond. The charge density distribution shows that Zr and N atoms form a strong Zr-N-Zr covalently bonded chain.