Structural and elastic properties, Vickers hardness and Debye temperature of (B1) BP: DFT study

Salah Daoud

doi:10.14419/ijpr.v8i1.30695

Abstract

A theoretical study of the structural parameters and elastic constants of boron phosphide (BP) compound with cubic rocksalt structure has been carried out using ab-initio density functional theory (DFT) and density functional perturbation theory (DFPT) calculations based on the plane-wave and pseudopotential (PW-PP) approach. Elastic anisotropy factors, Cauchy pressure, inverted Pughâ€™s ratio, aggregate mechanical moduli (shear modulus, Young's modulus and Poisson's ratio), Vickers hardness HV, elastic wave velocity as well as the Debye temperature Î¸D and the melting point have been also calculated. Our obtained results are in general in good agreement with other data of the literature. The deviation between our obtained value (4.225 Ã…) of the lattice constant and the theoretical value (4.282 Ã…) of the literature is around 1.33%, while that between our obtained value (169.7 GPa) of the bulk modulus and the theoretical one (171 GPa) is only around 0.77%. The calculated values of HV and Î¸D were found at around 30.5 GPa and 1254 K (1314.4 K), respectively.Â Â

Highlights

Group III-V semiconducting compounds have attracted a great deal of attention [1,2,3,4,5,6,7,8,9,10,11,12,13] anticipating fabrication of important electronic devices [1]
To obtain the static properties of boron phosphide (BP) in cubic rock-salt (B1) phase, we calculated the total energies at about eight different volumes and fitted them with an equation of state
Replacing our value (169.7 GPa) of the bulk modulus B in the previous expression, the melting point Tm of B1-BP was theoretically estimated at around 2185.2 K, which is slightly lower than the theoretical value 2482 ± 300 K obtained from the elastic constant C11 reported in our previous work [13]

Summary

Introduction

Group III-V semiconducting compounds have attracted a great deal of attention [1,2,3,4,5,6,7,8,9,10,11,12,13] anticipating fabrication of important electronic devices [1]. They discussed the bonding parameter in terms of charge density, which suggests that the bonding of BP, BAs and BSb are less ionic than in other zincblende compounds (BN, GaN, AlN...etc) They found that BP semiconducting material transforms from the zinc-blende (B3) phase to rock-salt (B1) one at pressure 128 GPa; while Arbouche et al [5] found that the first order transition is from B3 phase to NiAs at pressure of around 133.26 GPa. Varshney et al [9] have investigated the structural phase transition under high pressure, elastic constants and thermodynamical properties of some III–V (BN, BP, and BAs) semiconducting compounds in cubic zincblende and rock-salt phases by formulating an effective interionic interaction potential. We compute the structural parameters, the elastic constants and some other physical quantities of B1-BP material using the PP-PW approach with the local density approximation (LDA) in the framework of the DFT and the DFPT

Computational method

Results and discussions

Elastic constants and related parameters

Sound velocity and Debye temperature

Conclusion