Density functional theory calculations of electronic structure and thermoelectric properties of K‐based double perovskite materials

Abstract

Structural parameters, elastic constants, electronic band structures, and thermoelectric properties of K 2 ABF 6 (A = Ag, Na, B = Rh, Pd, Ni, Nb, Ru, Ti) materials at zero pressure and elevated temperatures have been studied. The computations have been presented within the density functional theory using the Cambridge Serial Total Energy Package code. Special attention has been given to the thermoelectric properties of the studied materials for K-based double perovskite materials. The obtained results are generally found to be in good agreement with the available data in the literature. Other case, our results are predictions. The calculated lattice parameters are found to be less than 3% with those of experiments. All materials of interest are classified as ductile ones. An inspection of the band structure indicated that all materials under load are indirect bandgap semiconductors. The high Seebeck coefficient is shown by the semiconductors, while metals have the least Seebeck coefficient. The alloys possess high figure of merit (ZT) values, suggesting their applications in thermoelectric power generation.

DFT Investigations on the Thermoelectric, Electronic, Optoelectronic, Elastic, and Structural Properties of K 2 NaTIX 6 (X=I, Br, and Cl) Double Perovskite

“…The Thomas Charpin approach is employed to obtain the values of the elastic constant Cij [45]. The cubic structure must satisfy the Born and Huang criterion, which is as follows, in order to be mechanically stable; [46].…”

Thermoelectric properties of La1.96Sr0.04CuO4 for energy harvesting and storage applications

“…In the oxide family, La 2‐x Sr x CuO 4 may be a prominent candidate for thermoelectric cooling applications below room temperature 7 . Here, it is important to mention that the thermoelectric properties of a material depend on a dimensionless parameter termed ‘figure of merit ( ZT )’ 8,9 . The figure of merit is a function of three mutually coupled physical quantities, that is, electrical conductivity ( σ ), thermo‐power ( S ) and thermal conductivity ( λ ) as: .…”

“…7 Here, it is important to mention that the thermoelectric properties of a material depend on a dimensionless parameter termed 'figure of merit (ZT)'. 8,9 The figure of merit is a function of three mutually coupled physical quantities, that is, electrical conductivity (σ), thermo-power (S) and thermal conductivity (λ) as: ZT ¼ S 2 σT=λ. However, the total thermal conductivity may be separated into the electronic (λ el ) and lattice contributions of thermal conductivity (λ ph ) by: λ T ð Þ ¼λ ph þ λ el .…”