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Optoelectronic devices are being extensively employed nowadays that are vital to diverse range of the appliances. The exploration of apposite materials for such efficient devices appears to be challenging. So, this study recommends novel combinations of chalcogenides as high energy materials that are seldom ever described. Here, density function theory (DFT) is employed to analyze the phase stability, optoelectronic, mechanical, thermodynamic, and vibrational properties of tellurium-based ternary chalcogenides XScTe2 (X = Li, Rb) by utilizing Perdew–Burke–Ernzerhof-generalized gradient approximation (PBE-GGA) and HSE06 through CASTEP simulation code. The observed minimum magnitude of free energy for these structures is found to be well-consistent with the stability requirements of the thermodynamics that confirms their chemical stability. The indirect energy band gap declares them semiconductors. Significant absorption is noticed in the ultraviolet (UV) range of the electromagnetic spectrum. The mechanical properties determined through Voigt–Reuss–Hill approximation determine mechanical instability due to the appearance of some negative elastic constants. Pugh's ratios evaluated as larger than 1.75 while demonstrating its ductile nature. The comprehensive analysis of thermodynamic behavior declares that these are thermodynamically stable materials. The density functional perturbation theory (DFPT) delineates no imaginary frequencies signifying both these compounds as stable materials. The thorough examination suffices to identify these materials as effective ones for optoelectronic uses. [ABSTRACT FROM AUTHOR]

In the current study, the first principle technique that depends exclusively on density functional theory is used to explore the structural, optoelectronic and thermoelectric properties of scandium-based ternary chalcogenides XScSe2 (X = Li, Rb). The Full Potential Linearly Augmented Plane Wave (LAPW) method accompanied by PBE-GGA functional is used to determine the optimized lattice parameters of both chalcogenides. The valence band maxima (VBM) and conduction band minima (CBM) occur at the same wave vector having a significant direct band gap such as 1.42 eV for LiScSe2 and 1.54 eV for RbScSe2 leading to their semiconductor behavior. The results of the partial density of states (PDOS) of the considered substances reflect that 2s states of lithium, 3d states of each Rb and Sc, and 4p orbitals of Se are mainly responsible for the rise in electronic conductivity. The optical results show that these chalcogenides exhibit a significant rise in absorptivity and optical conductivity in the UV energy region when the photons are incident upon, where low reflectivity is noticed. The thermoelectric (TE) properties are also investigated through the BoltzTraP to understand the semi-classical Boltzmann transport theory. These results are prospective and provide a novel path for researchers to explore their potential applications in optoelectronic as well as thermoelectric devices. [ABSTRACT FROM AUTHOR]

The Density Functional Theory (DFT) calculations interpreted the electronic and optical alteration of Ruddlesden–Popper layered perovskite (Sr3Zr2O7) with substitutional doping of Ti‐, Hf‐, and Ti+Hf‐ atoms in place of Zr‐atoms by generating the oxygen vacancies (Vos) defect. Formation energy and phonon calculations confirmed that the studied composites are dynamically stable, and the lattice parameters of the considered RP perovskite with and without vacancy defects did not change by introducing a small concentration of doped elements. The doped Sr3Zr2O7 composites show band gap tuning in the presence and absence of Vos, which was 3.31 eV in pristine form, and localized states near the Fermi line due to dopant and Vos, which confirmed the quantized conductance in all composites and may be beneficial for overcoming uniformity issues in nonvolatile memory devices. Isosurface charge density calculations also verified this result by depicting the physical mechanism of charge accumulation and depletion in the layers of RP perovskite in the vicinity of defects, resulting in residual conducting filaments guiding its growth and leading it to a low resistance state. The photosensitive response of this layered perovskite also confirmed its use for memory storage applications. The valuable outcomes of this study predicted that Sr3Zr2O7+Ti+Hf is the most stable and, hence, the best composite for nonvolatile RRAM device applications. [ABSTRACT FROM AUTHOR]

DFT study on the structural, optoelectronic, thermodynamic, vibrational, and mechanical properties of Ruddlesden Popper (RP) perovskites Sr2XO4 (X = Zr, Hf) is made with the help of first principle simulation in the framework of WIEN2K code. The lattice constants in bohr unit are found to be a=7.313,b=7.313,c=23.346 for Sr2ZrO4, and a=7.310,b=7.310,andc=23.368 for Sr2HfO4. The calculated band gap values are 2.65 eV for Sr2ZrO4 and 2.58 eV for Sr2HfO4. The band structure and electronic density of states reveal the semiconductor nature of these materials having an indirect band gap. Also, Kramers–Krönig relations are used for optical analysis which unveils that these compounds are suitable for applications in optoelectronic. The vibrational investigations are done while using harmonic approximation. Phonon dispersion curves are plotted to observe the vibrational modes by DFPT to confirm the dynamical stability of studied compounds. Although few soft modes have appeared, however, these compounds are found to be thermally stable. Raman modes appeared at low and high frequencies whereas IR modes are noticed at intermediate frequencies for considered compounds. Upon thermodynamical examination, the maximum value of free energy at 1000 K is noted to be −1.95 eV for Sr2ZrO4 and −2.25 eV for Sr2HfO4. The elastic constants are calculated by using the Voigt–Reuss–Hill approximation. The calculated anisotropic values for these compounds are 1.077 (A) and 0.913 (A) which indicate that Sr2ZrO4 has isotropic behavior and Sr2HfO4 has anisotropic behavior. From our calculations, Voigt Young's modulus of Sr2ZrO4 and Sr2HfO4 is 266.99 (GPa) and 279.42 (GPa) along with Poison's ratio of 0.29 and 0.26, respectively. [ABSTRACT FROM AUTHOR]

In order to study any material the first principles approach has been considered an appropriate forum and deemed the best remedy to ensure the validity of the achievements/results obtained either theoretically or experimentally. We are, therefore, motivated to use this approach to explore the structural, optoelectronic and vibrational properties of Sb2S3 while utilizing the plane-wave pseudopotential technique and conjugate gradient method employed through the CASTEP simulation code. The crystal structure of Sb2S3 is optimized in orthorhombic phase having space group Pnma with lattice parameters a = 11.31 Å, b = 3.84 Å and c = 11.23 Å. It is noticed that magnitude of these lattice parameters approximately replicate the formerly reported theoretical as well as experimental results. The energy band gap is found to be 1.012 eV, which is utter evidence that the studied compound belongs to semiconductor category of the materials. The optical parameters unveil that Sb2S3 is capable to absorb wide range of radiations from the ultraviolet (UV) portion of the spectrum. The dynamical analysis through density functional perturbation theory (DFPT) shows that there is no soft mode which further ensures dynamical stability of Sb2S3. The optical analysis of the studied compound are enough to declare it a potential material for applications in solar cells. [ABSTRACT FROM AUTHOR]

First-principles simulation has been performed to investigate the structural, electronic and optical properties of two disulfide compounds, i.e. X S2 (X = Ta , Ti). The properties are examined through the density functional theory (DFT) with the implementation of Cambridge series total energy package (CASTEP) code. As regards, the structural and electronic analyses are done by Perdew–Burke–Ernzerhof-generalized gradient approximation (PBE-GGA) and hybrid Heyd–Scuseria–Ernzerhof (HSE06) functional and their results are compared herewith. The values of lattice parameters obtained through geometry optimization for TaS2 with GGA and HSE06 are a = b = 3. 2 7 Å and c = 1 2. 8 9 Å and a = b = 3. 3 1 Å and c = 1 2. 0 9 Å, respectively, while for TiS2 these parameters are found as a = b = 3. 3 9 Å and c = 5. 6 9 Å. These values are found in agreement with the experimental values. The electronic band structure, as well as density of states (DOS) of these structures, show their semiconducting nature with the direct bandgap of 1.9 eV (PBE-GGA) and 2.05 eV (HSE06) for TaS2 and 0.09 eV (PBE-GGA) and 0.13 eV (HSE06) for TiS2. The mechanical study of these compounds also has been anticipated using Voigt–Reuss–Hill approximation under the pressure range 0–30 GPa to show their stability by calculating the elastic parameters, i.e. Young's modulus, bulk and shear modulus, Poisson's ratio, Pugh's ratio and anisotropic factor. The analysis of optical properties divulges that TiS2 material possesses maximum absorptivity in the UV range of incident photon's energy with minimum energy loss and decrease in reflectivity. Our comprehensive study about the considered compounds delineates them as potential candidates for technological applications in optoelectronic devices. [ABSTRACT FROM AUTHOR]

The structural, elastic, charge conduction and photoresponsive properties of halide perovskites, i.e., CsBX3 (B = Pb, Sn; X = I, Br, Cl) are investigated using the full potential‐linearized augmented plane wave (FP‐LAPW) method in the frame work of density functional theory (DFT). Perdew Burke Ernzerhof (PBE) functional belonging to the generalized‐gradient approximation (GGA) is implemented. For the better estimation of electronic parameters, the Tran–Blaha modified Becke–Johnson (TB‐mBJ) potential is employed. The elastic parameters such as bulk modulus, shear modulus, Young's modulus, the Pugh's ratio, anisotropy factor, Poisson's coefficient, and melting temperature (Tm) are estimated within Voigt‐Ruess‐Hill approximations. The energy band structure results, total density of states (TDOS), partial density of states (PDOS) outcomes, and isosurface charge density contour plots disclose that Sn2+and I1− are more appropriate divalent cation and anion respectively, among all studied composites especially for the application of photoresponsive resistive random access memory (RRAM) devices. Moreover, partial density of states (PDOS) outcomes depict that conduction band formation is consequence of hybridization of electrons from p‐orbitals of divalent cations, i.e., Pb, Sn and I/Br/Cl halogen anions. Besides, regarding charge conduction Sn‐based composites offer minimal energy bandgap as compared to Pb‐based composites. The energy bandgap order for Sn‐based compounds is found as CsSnI3> CsSnBr3> CsSnCl3. The optical analysis renders that CsSnI3 have the capability to absorb a wide range of ultraviolet (UV), visible and infrared (IR) electromagnetic incident radiations thus, make it much suitable material for optoelectronic memristors and associated applications. [ABSTRACT FROM AUTHOR]

Herein, the layered perovskites Bi2XO4 (X = Be, Mg) have been taken into account to probe into their structural and optoelectronic behavior using an ab initio technique which is solely reliant on density functional theory (DFT). To compute an improved electronic bandgap and encounter accurate contribution from d/f electronic states, the Tran and Blaha‐modified Becke–Johnson functional is used systematically, which has been considered an adequate approach to overcome limitations of the PBE–GGA functional. The conduction band minima (CBM) and the valence band maxima (VBM) are located at different values of the wave vectors yielding a noticeable indirect energy gap such as 2.80 eV for Bi2BeO4 and 2.40 eV for Bi2MgO4, which discloses that studied perovskites belong to the semiconductor category. The density of states exposes that Bi‐6p states contribute in the conduction region in vicinity of 5 eV energy. Whereas Be‐s orbitals are contributing in the far region of the conduction bands. O‐2p states are located in lower energy range associated with valence bands. Large values of formation and cohesive energy of compounds indicate that these are more stable and not easily decomposable under ambient conditions. The minimal reflectivity endorses our contention that these perovskites might be very useful for potential applications in optoelectronics. [ABSTRACT FROM AUTHOR]

In order to cope with the energy crisis and global warming issues, researchers are rendering their efforts and paying attention to analyzing and fabricating hydrogen storage devices. That is why comprehensive investigations are made to unfold the structural, vibrational, mechanical, and optoelectronic properties of lithium borohydride (LiBH4), a hydrogen storage material. For this purpose, calculations of the structural properties were performed using local, nonlocal, and hybrid functionals within the framework of density functional theory. For the determination of lattice constants in the orthorhombic phase, local density approximation (LDA), Perdew‐Burke‐Ernzerhof (PBE), and Heyd‐Scuseria‐Ernzerhof (HSE06) density functionals were chosen, and their results were compared with available experimental and theoretical studies. In order to determine infrared (IR) and Raman active modes of vibrations, vibrational spectroscopy was utilized through density functional perturbation theory. Li, B, and H atoms are noted to contribute in different modes of vibrations among various ranges of frequencies, that is, 0 to 400 cm−1, 1100 to 1300 cm−1, and 2250 to 2400 cm−1. Values of the energy band gap are found to be 6.35, 6.81, and 7.58 eV for LDA, PBE, and HSE06 functionals, respectively, indicating the insulating nature of LiBH4. Such fascinating properties make these compounds promising candidates for future applications in optoelectronic devices. Mechanical analysis revealed that LiBH4 is a brittle and stiffer material. Other optical properties, such as dielectric constant, refractive index, reflectivity, absorptivity, conductivity, and loss function, were also calculated with the assistance of the well‐recognized Kramer‐Kronig relation. The energy loss function depicted a plasma frequency of 13.7 eV, noted from the highest loss peak. It can be concluded that this material is not only suitable for hydrogen storage but also for optoelectronic devices. [ABSTRACT FROM AUTHOR]

Summary: Nowadays, there exists an increasing trend of investigating ternary perovskite oxide materials because of their wide applications in solar cells and similar electronic and optoelectronic devices. This work describes a systematic study performed through state‐of‐the‐art ab initio density functional theory (DFT) approach associated with the magnetic, electronic, and thermoelectric behavior of XTaO3 (X = alkali metals i.e., Rb, Fr) tantalate perovskite oxides. These compounds are found to be semiconductor because both materials have shown significant values of the band gap energy, that is, indirect energy band gap of 1.12 eV (↑↓) in RbTaO3 and direct band gap of 1.08 eV (↑↓) in FrTaO3. The calculated formation energies appear to be decreasing such as −3.54 and −1.92 eV for RbTaO3 and FrTaO3, respectively. The analysis through projected density of states discloses that Fr‐6p and 2p states from anion sites have shown overall contribution in forming the highest edge of the valence band (VBM), while, Ta‐5d states have depicted chief role to form major part of the conduction band minima, thereby, contributing in electronic conductivity. The much better values of thermoelectric parameters such as power factor of (5.5062 × 1013 W.m−1.K−2.s−1) and figure of merit (0.82) demonstrate that RbTaO3 is more dominating and promising semiconducting material which would, comparatively, be deemed an appropriate candidate for application in developing efficient thermoelectric devices. Finally, on the bases of above cited facts and the already existing data on similar perovskite oxides, it can be speculated that the studied compounds seem potential candidates to understand underlying physics and for possible applications in thermoelectric and other allied devices. [ABSTRACT FROM AUTHOR]

The structural and optoelectronic properties of ATiO3 (A = Rb, Cs, and Fr) perovskite oxides in the cubic phase are investigated using an ab initio method based on density functional theory. The exchange correlation function is determined by the full-potential linearized augmented plane wave approach. RbTiO3 shows an indirect band gap energy of 2.43 eV, whereas direct band gap energies of 1.90 eV and 1.66 eV are calculated for CsTiO3 and FrTiO3 compounds, respectively. The electronic density of states reveals that d states from A-cations (Rb, Cs, and Fr), along with Ti-d states, are located in the conduction band. The charge density demonstrates the ionic nature of the A-cations (Rb, Cs and Fr), while oxygen atoms share isolines with Ti atoms, leading to covalent bonds between them. Optical analyses show that the considered compounds have good optical conductivity and absorptivity when high-energy photons are incident on the surface of the materials, in particular showing minimal reflectivity. In view of these results, we consider that perovskites belong to a semiconductor category of materials suitable for application in photovoltaic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The aim of this study is to figure out better metal dopants for CeO2 for designing highly efficient non-volatile memory (NVM) devices. The present DFT work involves four different metals doped interstitially and substitutionally in CeO2 thin films. First principle calculations involve electron density of states (DOS) and partial density of states (PDOS), and isosurface charge densities are carried out within the plane-wave density functional theory using GGA and GGA + U approach by employing the Vienna ab initio simulation package VASP. Isosurface charge density plots confirmed that interstitial doping of Zr and Ti metals truly assists in generating conduction filaments (CFs), while substitutional doping of these metals cannot do so. Substitutional doping of W may contribute in generating CFs in CeO2 directly, but its interstitial doping improves conductivity of CeO2. However, Ni-dopant is capable of directly generating CFs both as substitutional and interstitial dopants in ceria. Such a capability of Ni appears acting as top electrode in Ni/CeO2/Pt memory devices, but its RS behavior is not so good. On inserting Zr layer to make Ni/Zr:CeO2/Pt memory stacks, Ni does not contribute in RS characteristics, but Zr plays a vital role in forming CFs by creating oxygen vacancies and forming ZrO2 interfacial layer. Therefore, Zr-doped devices exhibit high-resistance ratio of ~ 104 and good endurance as compared to undoped devices suitable for RRAM applications. [ABSTRACT FROM AUTHOR]

Transition metal model pseudopotential (TMMP) technique has been applied to study the short range order (SRO) in nickel alloys Ni100-x--Rhx and Ni100-x--Pdx and a copper alloy Cu100-x--Rhx (x = 2, 5, 8, 11 at. %). All these transition metal alloys form fcc solid solutions for the chosen compositions. The static electrical permittivity ε(q) was taken from the Hubbard--Sham model and/or Geldart--Vosko model to account for the exchange energies and correlation correction factors. Ordering energies and the Warren--Cowley SRO parameters have been calculated for all these alloys. Both models gave almost the same values for both the ordering energies and the Warren--Cowley SRO parameters. The TMMP model is found to predict the correct sign of SRO parameters for all these alloys. [ABSTRACT FROM AUTHOR]

In the present article, the DFT based computational manufacturing for hydrogen fuel cell has been performed because hydrogen storage applications as one of the utmost explored research fields of the modern era. The discovery of novel and potential hydride perovskites materials has developed the current attention for hydrogen fuel cell and related applications. The double hydride perovskite Cs 2 CaTlH 6 , Cs 2 SrTlH 6 , Cs 2 BaTlH 6 materials are promising for the computational manufacturing of hydrogen fuel cell because calculated tolerance factors for the considered materials are listed as Cs 2 CaTlH 6 (0.90) > Cs 2 SrTlH 6 (0.86) > Cs 2 BaTlH 6 (0.84) illustrating the structure stability and compatibility along with metallic electronic behavior favorable for hydrogen storage devices. The mechanical parameters for the considered materials are also calculated to encounter the Born reliability, stability and compatibility criterion. The Pugh's ratio, poison coefficient and Cauchy pressure calculations confirmed the brittle character favorable for hydrogen fuel cell. Furthermore, gravimetric ratios recommended that the considered materials are suitable and favorable for hydrogen fuel cell as hydrogen fuel can sustain for longer time and contribute extraordinary assistances in transportation handling applications and multiplicity of power. In addition, the considered materials are thermodynamic and vibrational symmetry as no soft (imaginary) mode of phonon in dispersion curve is observed. In short, the considered materials Cs 2 CaTlH 6 , Cs 2 SrTlH 6 , Cs 2 BaTlH 6 are novel, significant and potential candidates for the hydrogen fuel cell and motivate the experimental researcher to synthesize these materials for experimental manufacturing of hydrogen fuel cell to meet the energy demand of the present day., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Malik Shafqat Hayat reports was provided by Emerson University Multan. Malik Shafqat hayat reports a relationship with Emerson University Multan that includes: employment. The authors belong to a back ward areas of the country (Pakistan) but are very much interested in study particularly in the research work. Due to lack of sources, authors are interested in DFT based computational work. No funding source yet have been achieved., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Context: In the present work, the cubic phase of the chalcogenide materials, i.e., A 2 MoSe 4 (A =Li, K) is examined to explore the structural, optoelectronic, magnetic, mechanical, vibrational, and thermodynamic properties. The lattice parameters for Li 2 MoSe 4 are found to be a= 7.62 Å with lattice angles of α=β=γ=90° whereas for K 2 MoSe 4 , a= 8.43 Å, and α=β=γ=90°. These materials are categorized as semiconductors because Li 2 MoSe 4 and K 2 MoSe 4 exhibit direct energy band gap worth 1.32 eV and 1.61 eV, respectively through HSE06 functional. The optical analysis has declared them efficient materials for optoelectronic applications because both materials are found to be effective absorbers of ultraviolet radiations. These materials are noticed to be brittle while possessing anisotropic behavior for various mechanical applications. The vibrational properties are explored to check the thermal stability of the materials. On the basis of thermodynamics and heat capacity response, Li 2 MoSe 4 is more stable than K 2 MoSe 4 . The results of our study lay the groundwork for future research on the physical characteristics of ternary transition metal chalcogenides (TMC)., Methods: These physical properties are explored for the first time while using a first-principles approach based on density functional theory (DFT) in the framework of Cambridge Serial Total Energy Package (CASTEP) by Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) functional. However, GGA+U and HSE06 are also employed to improve electronic properties. Kramers-Kronig relations are used to evaluate the dielectric function with a smearing value of 0.5 eV. Voigt-Reuss-Hill approximation is used for seeking the elastic response of these materials. The thermodynamic response is sought by harmonic approximation. The density functional perturbation theory (DFPT) approach is used for investigating atomic vibrations., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Atomic Layer Deposition (ALD) was used for a tri-layer structure (HfO 2 /Al 2 O 3 /HfO 2 ) at low temperature over an Indium Tin Oxide (ITO) transparent electrode. First, the microstructure of the fabricated TaN/HfO 2 /Al 2 O 3 /HfO 2 /ITO RRAM device was examined by the cross-sectional High-Resolution Transmission Electron Microscopy (HRTEM). Then, Energy Dispersive X-ray Spectroscopy (EDS) was performed to probe compositional mapping. The bipolar resistive switching mode of the device was confirmed through SET/RESET characteristic plots for 100 cycles as a function of applied biasing voltage. An endurance test was performed for 100 DC switching cycles @0.2 V wherein; data retention was found up to 10 4 s. Moreover, for better insight into the charge conduction mechanism in tri-layer HfO 2 /Al 2 O 3 /HfO 2 , based on oxygen vacancies (V OX ), total density of states (TDOS), partial density of states (PDOS) and isosurface three-dimensional charge density analysis was performed using WEIN2k and VASP simulation packages under Perdew-Burke-Ernzerhof _Generalized Gradient approximation (PBE-GGA). The experimental and theoretical outcomes can help in finding proper stacking of the active resistive switching (RS) layer for resistive random-access memory (RRAM) applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The first-principles approach has been used while employing the Perdew-Burke-Ernzerhof exchange-correlation functional of generalized gradient approximation (PBE-GGA) along with the Hubbard parameter to study the structural, optoelectronic, mechanical and magnetic properties of titanium-based MAX materials Ti 3 AC 2 (A = P, As, Cd) for the first time. As there is no band gap found between the valence and conduction bands in the considered materials, these compounds belong to the conductor family of materials. A mechanical analysis carried out at pressures of 0 GPa to 20 GPa and the calculated elastic constants C ij reveal the stability of these materials. Elastic parameters, i.e. , Young's, shear and bulk moduli, anisotropy factor and Poisson's ratio, have been investigated in the framework of the Voigt-Reuss-Hill approximation. The calculated values of relative stiffness are found to be greater than ½ for Ti 3 PC 2 and Ti 3 AsC 2 , which indicates that these compounds are closer to typical ceramics, which possess low damage tolerance and fracture toughness. Optical parameters, i.e. , dielectric complex function, refractive index, extinction coefficient, absorption coefficient, loss function, conductivity and reflectivity, have also been investigated. These dynamically stable antiferromagnetic materials might have potential applications in advanced electronic and magnetic devices. Their high strength and significant hardness make these materials potential candidates as hard coatings., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The structural, electronic and thermoelectric properties of AZr 1-x M x O 3 (A = Ba, Ca, Sr; M = Al, Cu, x = 0.25) without and with an oxygen vacancy (Vo) have been unveiled using the Perdew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA) functional along with Tran-Blaha modified Becke-Jonhson (TB-mBJ)approximation based on Density Functional Theory (DFT) in the framework of WIEN2k code for memristors applications. Moreover, isosurface charge density plots have been calculated by using Vienna ab initio Simulation Package (VASP) simulation code. The analysis of structural parameters reveals that substituting Zr 4+ with Al 3+ and Cu 2+ causes the lattice distortion which tends to increase in the presence of Vo along with dopant. The study of band structure, density of states (DOS) and isosurface charge density plots predict the enhanced charge conduction and formation of conducting filaments (CFs) for all composites with dopant and/or Vo. Moreover, spin polarized density of states for Cu doped composites has also been calculated to confirm the large exchange splitting of Cu-3d states. The thermoelectric characteristics of considered composites have also been explored using the Boltztrap code to better explain the semi-classical Boltzmann transport theory. Thermoelectric parameters confirm the semiconductor nature of all composites, ensuring the compatibility for memristors and thermoelectric devices applications. In addition to this spin polarized thermoelectric behavior of Cu doped composites that ensure the contribution of spin down (↓) states of Cu for charge transport mechanism. The SrZrCuO 3 +Vo composite is found most promising candidate followed by BaZrCuO 3 for memristors applications while, CaZrCuO 3 is found most suitable amongst studied composites for thermoelectric devices., Competing Interests: Declaration of competing interest No conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The mechanical, magnetic and thermoelectric properties of spin polarized XGaO 3 (X = Sc, Ti, Ag) perovskite oxides in cubic phase have been investigated using LDA + U functional through ab-initio study based on density functional theory (DFT) in the framework of WIEN2K simulation code. The Full Potential Linearized Augmented Plane Wave (FP-LAPW) technique along with PBE-GGA functional have been used to optimize the systems and determining exchange-correlation potential. However, in order to address on-site self-interactions error and overcome limitations of PBE-GGA functional, LDA + U has been employed because Hubbard parameter 'U' is found an appropriate remedy to consider on-site self-interactions, and to calculate improved electronic energy band gap. All spin polarized band structures reveal indirect band gap with different energies E g (eV) such as ↑↓ 0.98 eV for ScGaO 3 , ↑1.05 eV and ↓1.70 eV for TiGaO 3 , ↑1.13 eV and ↓2.19 eV for AgGaO 3 . Thus, all compounds are semiconductor in nature. The analysis of spin polarized total and partial density of states unveil that ScGaO 3 is non-magnetic material, whereas, TiGaO 3 and AgGaO 3 are characterized by strong exchange splitting of 3d (Ti) and 4d (Ag) states with significant spin magnetic moments, i.e., 1.0002 μ B and -2.0002 μ B , respectively. The elastic constants, i.e., Bulk, Young and Shear moduli, Poisson's coefficient, Anisotropy factor, Pugh's ratio, Cauchy pressure and melting temperature are calculated through Viogt-Reuss-Hill approximation. The thermoelectric response of the considered perovskites has been determined through semi-classical Boltzmann transport theory in the framework of BoltzTraP simulation code. Basic understandings of the mechanical, magnetic and thermoelectric properties of these compounds are studied for the first time in this manuscript., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this paper, theoretical calculations for electronic band structure, the density of states, the optical and thermoelectric response of orthorhombic LaXO 3 (X = Cr, Mn, Fe) compounds are calculated. The Full Potential Linearized Augmented Plane Wave plus local orbital (FP-LAPW + lo) method is used in the context of density functional theory. Band gaps of three compounds are determined using Wu Cohen Generalized Gradient approximation with additional U potential (WC-GGA + U). Ferromagnetism is observed due to strong p-d hybridization and is justified by observed magnetic moments across individual atoms and at interstitial regions, and exchange constants are also reported. Optical properties are explained by calculating real and imaginary parts of the dielectric function, refractive index (n), extinction coefficient (k), reflection coefficient (R), the absorption coefficient (α), and energy loss spectrum (L). High value of dielectric constant, very small reflectivity and lower energy loss factor in, visible to ultraviolet region favours them for optoelectronic devices. We also computed the thermoelectric properties, including Seebeck coefficient, thermal and electrical conductivity and power factor as a function of temperature by combining results from DFT and Boltzmann transport theory. The phonon dispersion curve shows the stability of the current structures., (Copyright © 2019 Elsevier Inc. All rights reserved.)