The structural and electronic properties of BAs and BP compounds and BPxAs1-x alloys

The structural and electronic properties of BAs and BP compounds and BPxAs1-x alloys have been investigated by full potential linearized augmented plane wave (FP-LAPW) method based on DFT The total energies and electronic band structures of these compounds have been calculated for different approximations of exchange-correlation energy. The comparative study has showed that the PW-GGA is the best one to produce the measured structural quantities of the compounds. such as the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. The electronic quantities of the compounds, such as the width of the valance band and energy gaps at high symmetry points have been found to be in good agreement with the corresponding measured ones when the compounds were defined by the lattice constants of PW-GGA scheme. The PW-GGA approach was also applied on BPxAs1-x alloys for obtaining the variation of the equilibrium lattice constants, bulk moduli. and minimum energy gaps as a function of the phosphorus concentration within the range of 0 < x < 1. It is found that, while the equilibrium lattice constants of BPxAs1-x alloys follow the corresponding values of Vegard's linear rule closely, the bulk moduli and energy gaps leave the values of linear concentration dependence rule by a small and non-smooth bowing (C) 2009 Elsevier B.V. All rights reserved.