Computational study of structural and elastic properties of random AlGaInN alloys

TL;DR

This paper provides a comprehensive computational analysis of the structural and elastic properties of cubic AlGaInN alloys using a parametrized Keating valence force field model based on DFT calculations, including concentration dependence and sensitivity analysis.

Contribution

It introduces a detailed parametrization of the Keating model for AlGaInN alloys and compares results with experimental data and other computational methods.

Findings

Lattice constant varies with composition and matches experimental trends.

Elastic constants depend quadratically on alloy composition.

Results are sensitive to computational procedures used in the Keating model.

Abstract

In this work we present a detailed computational study of structural and elastic properties of cubic AlGaInN alloys in the framework of Keating valence force field model, for which we perform accurate parametrization based on state of the art DFT calculations. When analyzing structural properties, we focus on concentration dependence of lattice constant, as well as on the distribution of the nearest and the next nearest neighbour distances. Where possible, we compare our results with experiment and calculations performed within other computational schemes. We also present a detailed study of elastic constants for AlGaInN alloy over the whole concentration range. Moreover, we include there accurate quadratic parametrization for the dependence of the alloy elastic constants on the composition. Finally, we examine the sensitivity of obtained results to computational procedures commonly employed in the Keating model for studies of alloys.