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In this study CoZrMnSb, a quaternary Heusler alloy has been explored utilizing the density functional theory based simulation package WIEN2k. The structural analysis exhibits an X1-type structure with a relaxed lattice constant of 6.27 Å in ferromagnetic phase. The band structure calculations show its half-metallic nature with full spin polarization states around the Fermi level at 0.56 eV energy. In addition, the magnetic moment is calculated to be 1.0 μB, which is in accordance with the Slater Pauling rule (Mtot = (Ztot–24) μB). The study shows the d-d hybridization of the transition metals Co, Zr, and Mn elements. Further, optoelectronic performances in terms of dielectric function, reflectivity, energy loss function, absorption coefficient have been determined for a range of photon energy up to12 eV (ultraviolet region). In optoelectronic applications, absorption of this material in visible light enhances its significance. The thermoelectric properties with chemical potential and thermodynamic properties in the pressure range of 0–40 GPa and temperature range of 0–1200 K have been analysed. Specific heat capacity and Debye temperature authenticate similar metallic behaviour of CoZrMnSb alloy at temperature versus pressure variations. At room temperature, the chemical potential study suggests high figure of merit ~ 0.9, which makes it a potential thermoelectric material. The suggested material has a high Seebeck coefficient and low thermal conductivity, making it a better match for waste heat recovery and spintronic applications. [ABSTRACT FROM AUTHOR]

Summary: The full‐potential linearized augmented plane wave (FP‐LAPW) method was employed in the framework of density functional theory (DFT) and semi‐classical Boltzmann transport theory to compute the electronic, elastic, mechanical, thermal, and thermoelectric characteristics of PbSnO3. The properties are derived using a variety of exchange correlations, that is, local density approximations (LDA), Perdew Burke Ernzerhof generalized gradient approximation (PBE‐GGA), Wu‐Cohen (WC‐GGA), Engel‐Vosko GGA (EV‐GGA) and Perdew Burke‐Ernzerhof generalized gradient approximation improved for solids (PBEsol‐GGA), modified Becke‐Johnson GGA, (mBJ‐GGA), new modified Becke‐Johnson GGA (nmBJ‐GGA), and unmodified Becke‐Johnson GGA, (unmBJ‐GGA). In order to accurately describe the characteristics of the perovskite materials, a new modified Becke Johnson (nmBJ) potential is used. In comparison to other computations, the obtained band gap of nmBJ (3.08 eV) is consistent with the other theoretical and experimental findings. The results of our calculations show that PbSnO3 has a direct band gap. In addition, the bulk modulus, elastic constants, Poisson's ratio, shear modulus, anisotropy, and Young's modulus are calculated. The transport theory based on BoltzTraP code is used to calculate electronic transport characteristics such as electrical conductivity and thermal conductivity, Hall‐coefficient, and so on in the temperature range 100 to 1200 K. Furthermore, the thermal characteristics such as Debye temperature, specific heat capacity, entropy and thermal expansion coefficient have been analyzed with quasi‐harmonic Debye model. [ABSTRACT FROM AUTHOR]

Summary: An ever‐increasing demand for energy due to increasing usage is driving the scientists to find out materials for their technological applications. In this regard, thermoelectric materials are considered to be excellent candidates as energy sources. Further, for the suitability of materials in device fabrication, the study of various thermophysical parameters is always required. We have therefore tried to explore various performances of SrCeO3 perovskite, systematically using density functional theory with different potentials. The electronic band structure profile of SrCeO3 shows semiconducting behaviour in the ground state. Thermoelectric performance indicators like Seebeck coefficient, thermal conductivity, electrical conductivity, and power factor have been estimated within temperature 0 to 700 K. Interestingly, SrCeO3 displays a figure of merit value 0.27 at 700 K. [ABSTRACT FROM AUTHOR]

• Half metallic behavior observed for PrFeO 3 and NdFeO 3 using modified Becke Johnson, applicable to spintronic devices. • Thermoelectric Efficiency is 0.38 for PrFeO 3. • NdFeO 3 and PrFeO 3 follows Anharmonic effect (Debye T3 law). • RFeO 3 block UV light and can be used as UV absorbers. We have investigated the rare-earth ferrites perovskite RFeO 3 (R = Pr, Nd) for their structural, electronic, magnetic, optical, thermodynamic, and thermoelectric behavior using DFT as incorporated in WIEN2K software package. We have used FPLAPW method with exchange–correlation potentials: GGA, mBJ, and mBJ + U for investigating the current problem. For electronic properties, we have studied the band profile, density of states, and electronic density of RFeO 3. The band profile of RFeO 3 comes out to be half-metallic in mBJ + U. Further, optical properties have been computed corresponding to photon energy (0–10 eV). Thermodynamic examination of these compounds is performed using the Quasi-Harmonic Debye model. Consequently, the thermodynamic parameters' variation has been examined with temperature (0–1200 K) as well as pressure (0–40 GPa). Finally, we have evaluated the thermoelectric parameters using BoltzTrap code, and their variation with temperature (50–1200 K) and chemical potential (−2 to 2 eV) has been presented. We have obtained a maximum thermoelectric efficiency of 0.38 for PrFeO 3 perovskite, and it is found that it increases with temperature. These materials are suitable to be used as a source in spintronic devices and UV absorbers. [ABSTRACT FROM AUTHOR]

Novelty statement The CsMgX 3 (X=Cl and Br) compounds are investigated with respect to their electronic, thermoelectric and optical properties using FP-LAPW method with PBE-GGA and mBJ-GGA potentials. One of the novelties in the compounds noticed that they have excellent thermoelectric efficiency measured bypower factor (PF), henceforth figure of merit (ZT). We predict PF value 2.75 x1011 and 3.98 x1011W/K2ms for CsMgCl 3 and CsMgBr 3 , respectively at room temperature, which increases as temperature increases. Further, these materials display ZT values of 0.69 and 0.75 at room temperature, which approach to 0.97 and 0.99 at certain chemical potential for CsMgCl 3 and CsMgBr 3 , respectively. Consequently, promising materials for thermoelectric applications. [Display omitted] • Electronic band profile exhibit wide band gap of 6.35 and 4.26 eV, in CsMgCl 3 and CsMgBr 3 compounds, respectively. • Remarkable figure of merit, 0.69 and 0.75 at 300 K, which approaches to 0.97 and 0.99 at certain chemical potential for CsMgCl 3 and CsMgBr 3 , respectively. • Materials found suitable in UV region and can be employed as UV absorbers implanted in sensitive devices to protect from UV-rays. • Our work pronounces novel results and can be beneficial for the advancement in the thermoelectric applications as well. The electronic, thermoelectric and optical properties of cubic CsMgX 3 (X = Cl, Br) are performed using full potential augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ-GGA) approximation as exchange correlation potentials. The band profile of CsMgCl 3 and CsMgBr 3 using mBJ-GGA potentials exhibits indirect wide energy band gap of 6.35 and 4.26 eV, respectively. Further, thermoelectric properties are carried out as a function of temperature (100–1200 K) and chemical potential using BoltzTrap code. It has been found that thermoelectric efficiency increases with increasing temperature upto 1200 K. The figure of merit (ZT) values are calculated to 0.69 and 0.75 at room temperature for CsMgCl 3 and CsMgBr 3 , respectively. Furthermore, optical properties are computed in the energy spectrum (0–12 eV). These materials absorb light in ultra violet region and can be used as absorber of UV-rays. Also materials are suitable for thermoelectric power generator applications. [ABSTRACT FROM AUTHOR]

• DFT calculations on ferromagnetic Mn2CoCr with GGA and mBJ approximations. • Predicted specific heat at constant volume and approaches to Dulong-Petit limit. • Mn 2 CoCr is new material exhibits good thermoelectric properties. • Seebeck coefficient, thermal conductivity, power factor calculated for the first time. • Prediction on Debye temperature and thermal expansion coefficient. Heusler compounds have been promising materials for their applications in spintronic, memory and thermoelectric devices. The Mn 2 CoCr, a full Heusler compound, has been investigated here for its mechanical, thermodynamic and thermoelectric prospective for the first time using full potential linearized augmented plane wave (FP-LAPW) method in support of density functional theory (DFT). The estimation of total energy conferred to Fm-3m structure in ferromagnetic phase, which was in accordance to the others finding. The estimated total magnetic moment was found to be 5.02 (in the units of Bohr magneton), which was in accordance with the Pauling-Slater rule and available data. The electronic structure using generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) revealed its metallic nature in both the spin configurations. Further, we have calculated the thermodynamic and thermoelectric constants such as specific heat, Debye temperature, Gruneisen constant, thermal conductivity, Seebeck coefficient and power factor. Our predicted value of specific heat at constant volume is 66.6 J/mol.K at 300 K and 0 GPa, which at higher temperature (1000 K) followed Dulong-Petit limit. The power factor was calculated to be 25x1012 Wm-1K−2 at 500 K, demonstrating its suitability in thermoelectric applications. [ABSTRACT FROM AUTHOR]

• Using the first-principles method, the structural, optoelectronic, and transport properties of anti-perovskite Na 3 SCl compounds have been determined. • An essential direct energy bandgap (Eg) of 3.493 eV compounds is displayed in the band structure computed using the modified Becke–Johnson potential (mBJ). • The optical response was examined with respect to photon energy (eV) up to 12 eV in terms of dielectric constants, refractive index, extinction coefficient, and energy loss function. • The classical Boltzmann transport theory accounts for the transport properties such as the Seebeck coefficient, electrical and thermal conductivity, power factor versus temperature, carrier concentration, and chemical potential. In the present work, we give a thorough analysis of the cubic inverse-perovskite Na 3 SCl's structural, electrical, optical, and thermoelectric properties using the FP-LAPW approach within the context of DFT. PBE-GGA has espoused for exchange-correlation the potential for the evaluation of structural characteristics. A well-known accurate potential for the computation of electronic structures known as TB-mBJ has also been added along with PBE-GGA for the computations of band structures and their density of states. The probe of cohesive energy, formation energy, and elastic aspects demonstrates that the material under study is chemically, and thermodynamically stable. The obtained lattice parameters and other structural data of the investigated Na 3 SCl are in well agreement with the reported results of similar compounds. A direct band gap of 3.493 eV identified from the band structure for Na 3 SCl demonstrates the semiconducting character of the examined antiperovskite. Charge density contours analysis reveals that Na 3 SCl possesses an ionic nature, which is confirmed by electron localization function (ELF) analysis. We additionally assessed optical constants for the Na 3 SCl, such as the dielectric function, optical reflectivity, refractive index, and electron energy loss, with radiation up to 12 eV. Furthermore, variations in temperature-dependent thermoelectric features in terms of Seebeck coefficient, thermal conductivity, electrical conductivity, power factor, and figure of merit have been determined for the first time using the BoltzTraP code. The perovskite under study has a p-type semiconducting nature, as indicated by the estimated positive Seebeck value, and holes rather than electrons are the predominant charge carriers for conduction. The obtained substantial figure of merit along with the low thermal-to-electrical conductivity ratio for the examined inverse perovskite imply it is suitable for thermoelectric applications in devices. Our examined Na 3 SCl inverse perovskite offers a fruitful framework for enhancing comprehensive TE efficacy for TE usage and green energy generation. [ABSTRACT FROM AUTHOR]

• Type-I structure is stable structure for both FeCrTiZ (Z = Si, Ge) compounds. • Ferromagnetic nature results from integer magnetic moment values. • Direct band gap in spin-up of FeCrTiSi. • Indirect band gap in spin-up of FeCrTiGe. • High value of bulk modulus and Debye temperature. • High values of figure of merit which is accountable for thermoelectric generators. The objective of this work is to find the possible applications of the compounds as thermoelectric materials or alternate energy materials. In this regard, FeCrTiZ (Z = Si, Ge) quaternary Heusler compounds have been analyzed via investigating their stable structure and other physical properties by using comprehensive density functional theory executed in the WIEN2k package. The optimized lattice constants and other ground state parameters are found to be concurrent with the existing data. The spin-embraced electronic properties lead to the half-metallic character of the compounds on account of different behavior of the two spins. The obtained total magnetic moment ideally follows the Pauling-Slater rule and is also congruent to the available data. Furthermore, to study the lattice vibrational properties, the dependence of unit cell volume, bulk modulus, Debye temperature, and Gruneisen constant has been estimated within a certain temperature and pressure range by employing a Debye model of quasi-harmonic approximation. The thermoelectric parameters have also been estimated by employing the BoltzTrap code which gives significant values of the figure of merit for both compounds. [ABSTRACT FROM AUTHOR]

• All the V doped Hf 1-x V x O 2 (x = 0.25, 0.50, 0.75) alloys are found to have half-metallic character. • Spin up states are metallic and spin down semi-conducting. • Alloys exhibit magnetic moments 1.00, 2.00, and 3.00 μB. • The integer value of magnetic moment further confirms their half-metallic nature. • Furthermore, thermoelectric properties of these alloys have also been computed. • These alloys are suitable for magnetic, spintronic and thermoelectric applications. In this work, we have reported the first-principles calculations based on functional theory density on the structural, electronic, magnetic, bonding nature and thermoelectric properties of Hf 1-x V x O 2 alloys (x = 0, 0.25, 0.50, 0.75). For all the materials, the equilibrium structural parameters like that of lattice constant, bulk modulus and first pressure derivative of bulk modulus have been computed. The band profile and the density of states results demonstrate half-metallic nature for Hf 1-x V x O 2 alloys (x = 0.25, 0.50, 0.75). The calculated total magnetic moment was 1.0 μB/cell, 2.0 μB/cell, and 3.0 μB/cell, and the partial moment of V or local contribution is 1.08 μB, 1.85 μB, and 2.73 μB, respectively for Hf 1-x V x O 2 alloys (x = 0.25, 0.50, 0.75). The transport properties such as Seebeck coefficient, thermo power and thermal conductivity are found to have a great variation with V concentration. These alloys may find suitable applications in spintronic materials and in high temperature thermoelectric devices. [ABSTRACT FROM AUTHOR]

• High figure of merit of 0.64, 0.66, 0.7 for MgCeO 3 , CaCeO 3 , BaCeO 3 , respectively at 1200 K for their applications in thermoelectric devices. • Anharmonic effect (Debye T3 law) in XCeO 3 is observed. • XCeO 3 compound exhibit semiconducting nature with band gap (mBJ) 2.26 eV (MgCeO 3), 2.6 eV (CaCeO 3), 2.4 eV (BaCeO 3), respectively. • Maximum optical conductance MgCeO 3 , CaCeO 3 , BaCeO 3 are 4512 cm−1, 4440 cm−1, and 4633 cm−1, respectively. We report structural, electronic, mechanical, optical, thermodynamic, and thermoelectric properties of XCeO 3 (X = Mg, Ca, and Ba) perovskite using density functional theory as inculcated in WIEN2K code. In the structural perspective these perovskites are found crystalized in their cubic phase Pm-3 m (2 2 1). The electronic profiles show semiconducting nature of all inspected materials. We have included various potentials like LDA, GGA-PBE, mBJ, mBJ + SOC and HSE06 to estimate energy band gap of the considered materials. We have estimated band gap of 2.266, 2.619, 2.439 eV for the MgCeO 3 , CaCeO 3 and BaCeO 3 perovskites. The mechanical and dynamical stabilities of these compounds are assured by calculating mechanical properties and phonon band structure, respectively. Further, the optical parameters such as reflectivity, absorption coefficient, dielectric function, optical conductivity and energy loss are examined corresponding to photon energy within the energy range of 0 to 13 eV. These materials are active in UV-region and can be used as UV-absorber. Furthermore, thermoelectric properties are examined by evaluating Seebeck coefficient, thermal and electronic conductivities, figure of merit and power factor. Thermoelectric efficiency shows increasing behavior corresponding to temperature. Materials show good thermoelectric efficiency at 1200 K equivalent to 0.64, 0.66, 0.7 for MgCeO 3 , CaCeO 3 , BaCeO 3 , respectively. The thermodynamic stability of XCeO 3 is ensured by studying the behaviour of volume, bulk modulus, entropy, heat capacity, thermal expansion coefficient, Gr u ¨ neisen constant and Debye temperature corresponding to temperature and pressure. The novelty in these materials is found for their suggestive applications as UV absorber, thermoelectric power generators, temperature resistant materials. [ABSTRACT FROM AUTHOR]

In the present study, structural, electronic, optical, thermodynamic and thermoelectric properties of perovskites TlSiF 3 are explored using first-principles calculations based on density functional theory with different exchange-correlation approximations (LDA, PBE-GGA, WC-GGA, PBE-sol GGA, and mBJ-GGA). The computed structure, electronic and charge density plots using PBE-GGA ​+ ​TB-mBJ approximation show that TlSiF 3 is an indirect band gap semiconductor (1.73 ​eV gap along with R– M direction) having ionic and covalent bonding. The optical response is analysed and explained in terms of dielectric function, refractive index, extinction coefficient, optical conductivity, reflectivity, and absorption coefficient in the energy range from 0 to 10 ​eV. The thermoelectric transport behaviour of TlSiF 3 is computed as a function of temperature and chemical potential, μ − E F. Further, the thermoelectric transport behavior of TlSiF 3 is computed as a function of temperature and chemical potential μ − E F (eV). It has been observed that highest value of ZT (0.43) is attained at 1000 ​K with a power factor (PF) of 9.3 ​× ​1010WK−2m−1s−1for a fixed chemical potential. Under varying chemical potential at 300K in n-type region, it exhibits ZT value of 0.98, which is required for thermoelectric devices. Furthermore, pressure as well as temperature dependence of the thermodynamic parameters like Debye temperature, heat capacity, bulk modulus, thermal expansion coefficient, heat capacity, have been estimated with the help of GIBBS program based on quasi-harmonic Debye model. The structural properties of TlSiF 3 compound were determined and we assessed the thin-film photovoltaic efficiency of about 28.5%, and noticed as a promising absorbing material for solar cell device. The optimal value of ZT obtained for this compound is 0.44 ​at 1000K indicating the possibility of TlSiF 3 as an excellent material for thermoelectric applications at high temperature. [Display omitted] • The perovskite TlSiF 3 is explored using FP-LAPW method with different exchange correlation functional. • The computed electronic structure using TB-mBJ approximation show that TlSiF 3 is an indirect band gap(1.729) • The optical response advocated maximum absorption inthe visible region. • The estimated power factor reveals that at optimal charge carriers, n-type TlSiF 3 has a higher power factorof 1.60 ​× ​1010W/K2ms. • The thermodynamic properties are computed based on quasi-harmonic Debye model. [ABSTRACT FROM AUTHOR]