First principles investigation of structural, elastic, electronic and optical properties of ABi₂O₆ (A = Mg, Zn) with trirutile-type structure

Abstract

First principles calculations based on density functional theory with generalized gradient approximation are performed to investigate the structural, elastic, electronic, and optical properties of new bismuth oxides, ABi₂O₆ (A = Mg, Zn) with the trirutile-type structure. Initially, the geometry structures obtained by geometry optimization are consistent with the experimental values. The calculated structural parameters show a good agreement with the experimental results. The optimized lattice parameters, six independent elastic constants (C₁₁, C₁₂, C₁₃, C₃₃, C₄₄ and C₆₆), bulk modulus (B), shear modulus (G), Young’s modulus (Y), Pugh’s ratio (G/B), Poisson’s ratio (ν), and elastic anisotropy (A) are calculated and discussed. This is the first quantitative theoretical prediction of the electronic, elastic, and optical properties of these compounds. The investigation of the electronic band structures reveals that these compounds are electrical conductors, with contribution predominantly from the Bi 6p states. The analysis of the elastic constants and other moduli shows large anisotropy on elasticity and brittle behavior. The origins of features that appear in different optical properties of these two compounds have been discussed using band structures. The large reflectivity of the predicted compounds in the low energy region might be helpful in high-quality candidate materials for coating to avoid solar heating.

Keywords:

• MgBi₂O₆
• ZnBi₂O₆
• Ab initio calculations
• elastic, electronic, and optical properties

Public Interest Statement

In this research work, we have studied the structural, elastic, electronic, and optical properties of ABi₂O₆ (A = Mg, Zn) with trirutile-type structure using the plane-wave ultrasoft pseudo-potential technique, which is based on the first principle density functional theory with generalized gradient approximation. To the best of our knowledge, this is the first quantitative theoretical prediction of the electronic, elastic, and optical properties of these compounds. We hope that this work will help investigate the different properties of other materials of this group.

Additional information

Funding

Funding. The authors received no direct funding for this research.

Notes on contributors

Md. Atikur Rahman

Our research groups have studied to examine special properties such as structural, elastic, electronic, optical, and thermodynamic properties of different materials at ambient conditions and under pressure. All the calculations have been performed using the plane-wave pseudo-potential technique based on the density functional theory implemented in the CASTEP code with generalized gradient approximation. Very recently, our groups have also worked to prepare crystalline powder by solid-state reaction method by carbolite furnace. The composition and crystalline phase will be confirmed by X-ray powder diffraction. We have also synthesized single crystals of oxide materials by Bridgman method using modified horizontal Bridgman furnace.