Effect of pressure on electronic, magnetic, thermodynamic, and thermoelectric properties of tantalum‐based double perovskites Ba ₂ MTaO ₆ (M = Mn, Cr)

Abstract

Summary The tantalum‐based double perovskites Ba2MTaO6 (M = Mn, Cr) are studied to understand the effect of pressure on structural, electronic, magnetic, thermodynamic, and thermoelectric properties by means of density functional theory. Ba2MTaO6(M = Mn, Cr) perovskites' own maximum stability in ferromagnetic phase with calculated high magnetic moments of 4.02 and 3.0 μB at zero pressure. Ba2MTaO6 (M = Mn, Cr) perovskites display complete spin polarization, ensuing the half metallic behavior. Effect of high pressure on the electronic structure and magnetism was also studied. The compounds have wide band gap that varies from 2.63 to 2.56 eV as the pressure increases from 0 to 25 GPa in Ba2CrTaO6, while as in Ba2MnTaO6 band gap varies from 2.24 to 1.95 eV as the pressure increase from 0 to 25 GPa. The magnetic moment also shows a decreasing inclination with increase in pressure in both compounds. Also, we calculated the heat capacities, thermal expansion coefficients, Debye temperature and Grüneisen parameter by using the Debye model. Boltzmann's theory was employed to perform post DFT treatment to investigate the thermoelectric properties of the compounds.

Insight into various properties of rare‐earth–based inverse perovskites Gd 3 AlX (X = B, N)

“…The study of optical response is important for the materials sustainability, robustness, and consistency in optoelectronic application . These properties can be obtained by computing the complex dielectric function ε(ω) , which is written as ε ( ω ) = ε 1 ( ω )+ iε 2 ( ω ) ,…”

“…The study of optical response is important for the materials sustainability, robustness, and consistency in optoelectronic application. [51][52][53][54] These properties can be obtained by computing the complex dielectric function ε(ω), which is written as ε(ω) = ε 1 (ω)+iε 2 (ω) , where ε 1 (ω) is real part and ε 2 (ω) is imaginary part of the dielectric function. From dielectric function, we can obtain values of refractive index n(ω), absorption coefficient α(ω), reflectivity R(ω), and optical conductivity σ(ω).…”

Systematic understanding of f ‐electron–based semiconducting actinide perovskites Ba 2 MgMO 6 (M = U, Np) from DFT ab initio calculations

“…These layered alloys display a significant quantity of magnetism due to the fact of two magnetic sites especially B and B′, which probably contribute the aid of magnetism in such kind of systems. The magnetic behaviour can be understood from the oxide perovskites including Ba 2 FeMnO 6 and Ba 2 MTaO 6 (M = Mn, Cr) . Simple cubic perovskites especially BaCfO 3 and BaBkO 3 possess an essential quantity of magnetism in their corresponding lattice structures and also designate the half metallicity for which spin‐polarization effect is commonly seen in these materials.…”

“…The magnetic behaviour can be understood from the oxide perovskites including Ba 2 FeMnO 6 18 and Ba 2 MTaO 6 (M = Mn, Cr). 19 Simple cubic perovskites especially BaCfO 3 20 and BaBkO 3 21 possess an essential quantity of magnetism in their corresponding lattice structures and also designate the half metallicity for which spin-polarization effect is commonly seen in these materials. Currently, a lot of research is going on theoretically as well as experimentally to expand the properties of these fascinating alloys as having their surplus impact on modern era.…”

High cross‐plane thermoelectric performance of carbon nanotube sponge films

“…Thermoelectric (TE) materials find wide applications in energy recovery. 1,2 TE performance is usually accessed by ZT, which can be expressed as ZT = S 2 σT/k, where S denotes Seebeck coefficient, k thermal conductivity, σ electric conductivity, and T temperature. [3][4][5][6] The main obstacle to increase ZT lies in the interrelated σ and k, thus simultaneously optimization σ and k. [7][8][9] The lowdimensional (two-dimensional or one-dimensional) materials offer a route to overcome this difficulty, because of the greatly decreased k and the approximately unchanged σ and S with respect to that of the bulk material.…”