Density functional study of the mechanical and phonon properties of Al12X (X = Mo, Tc, Ru, W, Re, and Os) compounds

Abstract

By means of first principles calculations, we have studied the structural, elastic, and phonon properties of the Al12X (X = Mo, Tc, Ru, W, Re, and Os) compounds in cubic structure. The elastic constants of these compounds are calculated, then bulk modulus, shear modulus, Young's modulus, Possion's ratio, Debye temperature, hardness, and anisotropy value of polycrystalline aggregates are derived and relevant mechanical properties are compared with the available theoretical ones. Furthermore, the phonon dispersion curves, mode Gruneisen parameters, and thermo-dynamical properties such as free energy, entropy and heat capacity are computed and the obtained results are discussed in detail. (C) 2014 Elsevier Ltd. All rights reserved.