Ab initio calculation of the elastic properties and the lattice dynamics of the AlAsxSb1-x alloy under pressure

作者：Daoud K; Bouamama Kh^*; Djemia P; Cherif S M

来源：High Pressure Research, 2011, 31(2): 310-324.

DOI：10.1080/08957959.2010.545406

• phonon
• elastic constants
• AlAs
• AlSb
• density-functional perturbation theory (DFPT)
• virtual-crystal approximation (VCA)
• supercell

The lattice dynamics and the elastic properties of the ternary AlAsxSb1-x alloy have been studied using the density-functional perturbation theory within the local density approximation and employing the virtual-crystal approximation. We study the variation of the optical phonon frequencies (TO and LO), the high-frequency (epsilon) and static (epsilon 0) dielectric coefficients, the dynamic effective charge (Z*) and the elastic constants (C11, C12, C44) as a function of the composition (x) and the pressure. We have also predicted the behavior of the optical and acoustical phonons with composition x at the X and L high symmetry points under pressure and determined the Gruneisen parameter. We have found that no mechanical instabilities are associated with the structural transition at high pressures for all compositions.

• 出版日期2011