Theoretical investigations of structural, electronic and thermal properties of Ti2AlX(X=C,N)

We have carried out a first-principles total-energy calculations of the structural and the electronic properties for the series of H-phases compounds Ti2AlC and Ti2AlN. We have applied the full-potential linearized augmented plane waves (FP-LAPW) method based on the density functional theory (DFT) using the local-density approximation (LDA) and/or the generalized gradient approximation (GGA). The quasi-harmonic Debye model, using a set of total energy versus volume calculations obtained with the FP-LAPW method which is applied to study the thermal and vibrational effects. Temperature and pressure effects on the structural parameters, thermal expansions, heat capacities and Debye temperatures are determined from the non-equilibrium Gibbs functions.