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Investigation on the electronic structure, optical, elastic, mechanical, thermodynamic and thermoelectric properties of wide band gap semiconductor double perovskite Ba₂InTaO₆

Dar, Sajad Ahmad, Sharma, Ramesh, Srivastava, Vipul, Sakalle, Umesh Kumar
RSC advances 2019 v.9 no.17 pp. 9522-9532
Poisson distribution, absorbance, anisotropy, density functional theory, dielectric properties, electrical conductivity, electrons, energy, heat, mechanical properties, modulus of elasticity, photons, refractive index, semiconductors
In the present paper, double perovskite Ba₂InTaO₆ was investigated in terms of its structural, electronic, optical, elastic, mechanical, thermodynamic and thermoelectric properties using density-functional theory (DFT). The generalized gradient approximation (GGA) in the scheme of Perdew, Burke and Ernzerhof (PBE) and the modified Becke–Johnson (mBJ) potential were employed for the exchange–correlation potential. The computed lattice constant was found to be in agreement with the available experimental and theoretical results. The electronic profile shows a semiconducting nature. Further analysis of the complex dielectric constant ε(ω), refractive index n(ω), reflectivity R(ω), absorption coefficient α(ω), optical conductivity (ω) and energy loss function were also reported with the incident photon energy. The elastic constants were also calculated and used to determine mechanical properties like Young's modulus (Y), the shear modulus (G), Poisson's ratio (ν) and the anisotropic factor (A). The electrical conductivity (σ/τ) and Seebeck coefficient (S) also demonstrated the semiconducting nature of the compound with electrons as the majority carriers. The value of the power factor was calculated to be 1.20 × 10¹² W K⁻² m⁻¹ s⁻¹ at 1000 K. From thermodynamic investigations, the heat capacity and Grüneisen parameter were also predicted.