Fully analytic valence force field model for the elastic and inner elastic properties of diamond and zincblende crystals

Abstract

Using a valence force field model based on that introduced by Martin, we present three related methods through which we analytically determine valence force field parameters. The methods introduced allow easy derivation of valence force field parameters in terms of the Kleinman parameter $\zeta$ and bulk properties of zincblende and diamond crystals. We start with a model suited for covalent and weakly ionic materials, where the valence force field parameters are derived in terms of $\zeta$ and the bulk elastic constants $C_{11}$, $C_{12}$, and $C_{44}$. We show that this model breaks down as the material becomes more ionic and specifically when the elastic anisotropy factor $A=2C_{44}/(C_{11}-C_{12})>2$. The analytic model can be stabilised for ionic materials by including Martin's electrostatic terms with effective cation and anion charges in the valence force field model. Inclusion of effective charges determined via the optical phonon mode splitting provides a stable model for all but two of the materials considered (zincblende GaN and AlN). A stable model is obtained for all materials considered by also utilising the inner elastic constant $E_{11}$ to determine the magnitude of the effective charges used in the Coulomb interaction. Test calculations show that the models describe well structural relaxation in superlattices and alloys, and reproduce key phonon band structure features.

References in corpus (9)

• Gaussian Approximation Potentials: the accuracy of quantum mechanics, without the electrons
• Spontaneous polarization and piezoelectric constants of III-V nitrides
• A Spectral Analysis Method for Automated Generation of Quantum-Accurate Interatomic Potentials
• Comparison of two methods for describing the strain profiles in quantum dots
• Origin of non-linear piezoelectricity in III-V semiconductors: Internal strain and bond ionicity from hybrid-functional density functional theory
• First-principles perturbative computation of dielectric and Born charge tensors in finite electric fields
• A many-electron tight binding method for the analysis of quantum dot systems
• Computational study of structural and elastic properties of random AlGaInN alloys
• Theoretical analysis of influence of random alloy fluctuations on the opto-electronic properties of site-controlled (111)-oriented InGaAs/GaAs quantum dots

Cited by in corpus (1)

• Electronic structure evolution in dilute carbide Ge${}_{1-x}$C${}_x$ alloys and implications for device applications