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

• The first-principles calculations have been performed for cubic Al12X systems.
• Al12Mo, Al12Tc, Al12Ru, Al12W, Al12Re, and Al12Os compounds are considered.
• The structural, elastic and lattice dynamical properties are investigated.
• The Voigt–Reuss–Hill (VRH) approximation is used to predict polycrystalline properties.
• Mechanical and dynamical stability of the compounds are discussed.

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 Grüneisen parameters, and thermo-dynamical properties such as free energy, entropy and heat capacity are computed and the obtained results are discussed in detail.

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