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We have studied the structural, anisotropic elastic and electronic properties of Sr–Zn binary intermetallic compounds using first-principles plane-wave pseudo-potential method. Our calculated equilibrium lattice parameters are validated by comparison with available experimental data. Results of formation enthalpy have indicated that each intermediate compound is energetically stable, and they are all mechanically stable according to the criteria of elastic stability. For the first time, the calculated elastic constants have allowed us to characterize the elastic anisotropy of acoustic velocity. Additionally, mechanical parameters, such as bulk modulus B , shear modulus G , Young’s modulus E and Poisson’s ratio σ are deduced by means of Voigt–Reuss–Hill method. It is discovered that, with increasing concentration of Zn, the mechanical moduli and theoretical Vickers hardness of Sr–Zn compounds could be improved. Mechanical anisotropies are discussed by calculating different anisotropic indexes and factors. Finally, calculations on density of states and atomic charge populations are performed to reveal the underlying mechanisms of electronic structure. [ABSTRACT FROM AUTHOR]

Using first principles total energy calculations within the generalized gradient approximation (GGA), we have investigated the mechanical and thermodynamics properties of C 14-type Laves phases AMg 2 (A = Ca, Sr and Ba). Our results of equilibrium lattice parameters and formation enthalpy agree closely with previous experimental results. In particular we have discussed the thermodynamic stabilities and mechanical anisotropies of these phase structures. The polycrystalline elastic moduli have been deduced by Voigt–Reuss–Hill arithmetic approximation. Subsequently, the ductility and brittleness are characterized with the estimation from Pugh’s rule ( B / G ) and Poisson’s ratio. Additionally, the Debye temperature is calculated from the average elastic wave velocity obtained from bulk and shear moduli. The calculations of density of states and charge density difference are performed to reveal the underlying mechanism of electronic structure. Finally, variations of thermodynamic properties with temperature are predicted by calculating phonon frequencies combined within the quasi-harmonic approximation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Structural properties and electronic structure of Al2Zr and Al2Hf are studied. [•] Mechanical properties are well described and discussed. [•] The Debye temperature and anisotropic sound velocity are first assessed. [•] The bonding strength for Al–Zr bonding is stronger than that of Al–Hf bonding. [ABSTRACT FROM AUTHOR]