WIEN2k Code Research Articles

Structural, Elastic, Electronic, and Magnetic Properties of Full-Heusler Alloys Sc2TiAl and Sc2TiSi Using the FP-LAPW Method

In this article, the structural, elastic, electronic, and magnetic characteristics of both regular and inverse Heusler alloys, Sc2TiAl and Sc2TiSi, were investigated using a full-potential, linearized augmented plane-wave (FP-LAPW) method, within the density functional theory. The optimized structural parameters were determined from the minimization of the total energy versus the volume of the unit cell. The band structure and DOS calculations were performed within the generalized gradient approximation (GGA) and modified Becke–Johnson approaches (mBJ-GGA), employed in the Wien2K code. The density of states (DOS) and band structure (BS) indicate the metallic nature of the regular structure of the two compounds. The total spin magnetic moments for the two compounds were consistent with the previous theoretical results. We calculated the elastic properties: bulk moduli, B, Poisson’s ratio, ν, shear modulus, S, Young’s modulus (Y), and the B/s ratio. Additionally, we used Blackman’s diagram and Every’s diagram to compare the elastic properties of the studied compounds, whereas Pugh’s and Poisson’s ratios were used in the analysis of the relationship between interatomic bonding type and physical properties. Mechanically, we found that the regular and inverse full-Heusler compounds Sc2TiAl and Sc2TiSi were stable. The results agree with previous studies, providing a road map for possible uses in electronic devices.

Thermodynamic properties of MgFeH3 alloy

The main objective of this work is to improve the kinetic properties and desorption temperature in MgFeH3 by applying different pressures. The first principles study was used for this purpose using the WIEN2k code, and all the calculations proceeded without a spin channel. We have theoretically determined that MgFeH3 has 3.64 wt. % gravimetric hydrogen storage capacity. The cubic crystal structure significantly improves the formation energy as well as desorption temperature at higher pressures. Phonon dispersion curves predict that the stability of the compound decreases with increasing pressures. At the same time, DOS shows that d-states of Fe move from valence to conduction band with increasing pressures. In thermodynamic properties, we have calculated entropy, specific heat at constant pressure (Cp), thermal expansion coefficient (

Strain enhances the electrical and photocatalytic properties of tetragonal boron nitride

A promising 2D material for photovoltaic (PV) applications is boron nitride. Tetragonal Boron Nitride (t-BN) is the name of the revolutionary of 2D-material based on Boron Nitride. In this study, we investigated the electronic, optical, and electrical properties of tetragonal Boron Nitride (t-BN) under various strains. The modified Becke-Johnson Tran-Blaha exchange potential approximation (TB-mBJ) and the screened hybrid functional HSE06, which is included in the WIEN2K code, employed in this research. Tension-compression also, employed to control the band gap and electrical conductivity. We demonstrated that the band gap of t-BN and its electrical conductivity at − 8% significantly increase under compressive stress. According to the calculations, t-BN has better electronic properties and it has a higher electrical conductivity. As attraction decreases, the band gap of t-BN. Furthermore, we determined that the property semiconductor in t-BN has been transforming too metallic. The innovative nanomaterial t-BN can enhance the efficiency of solar cells since it has good electrical properties.

New investigated lead free double perovskite materials Rb2LiBiX6 (X= Cl, F, Br, I) for optoelectronics and solar cell applications via first principle calculations

The physical properties of cubic inorganic double perovskites Rb2LiBiX6 (X = Cl, F, Br, I) were investigated by using density functional theory (DFT) based on Wien2K code. The structural parameters obtained are calculated by using Murnaghan equation of state and Chapin's method. The results found by exploring the mechanical properties and the enthalpy of formation of the materials ensuring the stability of the materials. This research expansively investigates optical and transport properties of the fourth double perovskite Rb2LiBiCl6, Rb2LiBiF6, Rb2LiBiBr6 and Rb2LiBiI6 for optoelectronics devices and thermoelectric applications. The calculated indirect band gap values are 4.96, 3.62, 2.93 and 2.00 eV for Rb2TeF/Cl/Br/I6 respectively. Optical properties are discussed in terms of dielectric constants, absorption coefficient, refractive index and reflectivity. Utmost peaks absorption occurred in the ultraviolet region for all compounds, which confirm their useful employment for optoelectronic applications. The electron transport properties are studied by electrical conductivity, thermal conductivity, Seebeck coefficient, and figure of merit. ZT. The calculations are performed versus the temperature in the range of 100–1200 K using BoltzTraP code. The p-type semiconducting character of the inorganic double perovskites Rb2LiBiX6 (X = Cl, F, Br, I) has been forecast by transport properties analysis.

Optoelectronic properties of RuCrX (X = Si, Sn, Ge) Half Heusler alloys: a DFT study

The aim of this study was to investigate the structural, electronic, optical, and thermal properties of optoelectronic Half Heusler Alloys, RuCrX (X = Si, Sn, Ge). The characterizations of these Half Heusler Alloys, RuCrX (X = Si, Sn, Ge) have been performed using Density Functional Theory (DFT) through first-principles calculations with the aid of WIEN2K code. The Generalized Gradient Approximation (GGA) was utilized as an exchange-correlation function in WIEN2K-Package to optimize the structures.. To obtain the necessary observational quality and desired properties, Full Potential Linearized Augmented Plane Wave (FPLAPW) was applied. The calculation of the lattice constants and band gaps was crucial to determine suitable materials for specific optoelectronic applications. This study also emphasized the complex dielectric function and elastic properties leading to the imaginary part of the dielectric functions showed that compounds were optically metallic and transparent with ductile properties. Also, the optical spectra and band structure transitions were studied in detail. Hence, the study predicted that Half Heusler Alloys, RuCrX (X = Si, Sn, Ge), have the potential for applications in optoelectronic devices.

The optoelectronic application of CsSnI3 upon substitution with Pb: A DFT approach

AbstractThe efficiency of Pb substitution on the Sn site of CsSnI3 is studied theoretically utilizing DFT as employed by Wien2k code. The energetical, structural, and thermodynamic stability criteria have been fully explained for the studied compounds. Structural and mechanical properties have shown the thermodynamic stability of the studied compounds and their ability to be formed. From their electronic properties, the electronic band gap tuning is observed by systematically substituting Pb in CsSnI3. All these compounds (Pb/CsSnI3) have shown a direct band gap nature within the range 1.11–2.95 eV, a potential indication of their possible usage in fabricating solar cells. On further investigating of their optical properties, the most stable and optically active band gap for solar cell application is observed for CsSn0.75Pb0.25I3 and CsSn0.5Pb0.5I3. Furthermore, the measured minimum thermal conductivity of Pb/CsSnI3 is greatest along the [1 1 1] direction. While the direct proportion predicts that the crystal structure with Pb atoms is anharmonic. High melting temperature, thermal stability, a wide optically active region, and a low Debye temperature indicate plausible operable conditions of these compounds under wide ambient conditions. The optical properties, ductile nature, and the bond bending attributes illustrate that CsSnxPb1−xI3 has exciting potential to be used in flexible electronic devices, solar cells, and optical sensors.

First-Principles Studies on the Physical Properties of the Half Heusler RbNbCd and RbNbZn Compounds: A Promising Material for Thermoelectric Applications

This work focuses on study of the structural, electronic, thermodynamic and thermoelectric properties of RbNbCd and RbNbZn Half Heusler (HH), utilizing a full-potential linearized augmented plane wave (FP-LAPW) approach and the Boltzmann transport equation using a constant relaxation time approximation within the context of density functional theory (DFT) as embedded in the WIEN2k code. The structural analysis employed the generalized gradient approximation (GGA) and considered the Birch Murnaghan equation of state (EOS), which results in the stable phase for RbNbCd and RbNbZn. The positive phonon spectra indicate the dynamical stability of the studied RbNbCd and RbNbZn. The compounds under investigation that have no bandgap are metallic, as evidenced by their electronic properties. Their mechanical and thermal stability as well as their anisotropic and ductile character are confirmed by the various elastic and thermodynamic parameters. The lattice thermal conductivity has been calculated. This thorough analysis demonstrates the applicability of the studied RbNbCd and RbNbZn for thermoelectric applications.

First-principles calculations to investigate structural, electronic, magnetic, optical, mechanical and thermoelectric properties of rare-earth aluminate perovskite XAlO3 (X = Ce, Nd, Gd) compounds

The spin-polarized full-potential linearized augmented plane wave (FP-LAPW) approach based on density functional theory (DFT) is used to investigate the structural, electronic, magnetic, optical, mechanical and thermoelectric properties of aluminate perovskite XAlO3 (X = Ce, Nd, Gd) compounds. For the exchange correlation potential, we used both GGA and mBJ approximations within the FP-LAPW approach as implemented in the Wien2k code. XAlO3 compounds are most stable in their ferromagnetic (FM) form, according to the findings of an analysis of the acquired structural optimization. The calculated negative value of the formation energy predicts that the present compounds are thermodynamically stable and could be formed. Moreover, the values of elastic constants fully satisfy the elastic and mechanical requirements. The tolerance factor of XAlO3 satisfies the condition of creation for the perovskite compounds. As all, these parameters show that XAlO3 are mechanically, elastically stable and could be created. The investigation of band structure and DOS confirms the presence of half metallic (HM) ferromagnetism (FM) in CeAlO3 and NdAlO3, as well as semiconductor behavior in GdAlO3. The HM energy gap (Eg) is 3.116 eV (GGA) and 3.156 eV (GGA + mBJ); 2.748 eV (GGA) and 2.803 eV (GGA + mBJ), respectively. The calculated net magnetic moments of CeAlO3, NdAlO3 and GdAlO3 are around 1.0 μB, 3.0 μB and 7.0 μB, respectively, indicating their ferromagnetic FM character. Magnetic characteristics of XAlO3 are mostly contributed by Ce, Nd and Gd atoms, which play a major role in FM properties. The optical properties of XAlO3 are investigated by calculating the real ε1(ω), imaginary ε2(ω) parts of dielectric function ε(ω), refractive index n(ω), extinction coefficient k(ω), reflectivity R(ω), optical conductivity σ(ω), absorption coefficient α(ω) and loss function L(ω). Also, the thermoelectric properties, Seebeck coefficient (S), electrical conductivity (σ/τ), power factor (S2σ/τ), thermal conductivity (κ/τ), figure of merit (ZT) and specific heat capacity (CV) are calculated and discussed. The current study confirms the mechanical and thermal stability of HM-FM perovskites, which candidate them for thermoelectric and spintronic applications.

Exploring structural, electronic, magnetic, and optical properties of CeO2-X (X = Pt/Ni) doped and Pt-Ni co-doped CeO2 for optoelectronic applications

Employing DFT technique, we perform Pt/Ni doping and Pt-Ni co-doping into CeO2. We study the structural, electronic, magnetic, and optical properties of CeO2 with selected dopants using Wien2k code. Spin-polarized DOS illustrate non-magnetic character of pure CeO2 while Pt/Ni/Pt-Ni doping yields magnetism into CeO2 with magnetic moment values of 2.2502 μ B, 2.5683 μ B, and 3.9190 μ B, respectively. Active participation of Ce 4f-, Pt 4d- and Ni 3d-states at the Fermi level suggests remarkable improvement in the conduction process. p-d hybridization is observed and it produces good response in electronic properties. Pt:CeO2 and Pt-Ni:CeO2 exhibit blueshift while Ni:CeO2 exhibit redshift in absorption spectrum. We notice an enhancement in optical absorption and conductivity with decreased reflectivity of these proposed materials in the UV region. Tuning of absorption spectra and decrease in band gap of these materials indicate their uses for photocatalytic, photonic, optoelectronics and power electronic devices.

Study of mechanical, optical and transport aspirants of double perovskites Cs2XInI6 (X = Li, Na) for solar cells and clean energy applications

The double perovskites (DPs) are extensively explored materials owing to their potential for optoelectronic and thermoelectric devices. In current report, the density functional theory-based Wien2k code is utilized to check the electrical, mechanical, optical, and thermoelectric characteristics of Cs2XInI6 (X ​= ​Li, Na). The calculation of enthalpy of formation yields information about the thermodynamic stability, while computing the tolerance factor yields information about the structural durability. Elastic constant dependent, moduli of elasticity have been computed which confirm the ductile nature of Cs2LiInI6 and brittle nature of Cs2NaInI6. Utilizing modified Beck and Johnson potential (TB-mBJ) to measure the band structures and optical characteristics reveals the bandgaps of 1.23, and 1.64 ​eV for Li and Na-based DPs, respectively. Additionally, the optical behavior is elaborated by computing refractive index, dielectric constant and reflectivity. The broad absorption bands in visible range increases their potential for solar cells. BoltzTrap code is utilized to compute temperature-dependent transport parameters. The capability of these DPs for thermoelectric applications is determined by figure of merit in the range of 200–800 ​K.

Enhanced thermoelectric and optical response of Ag substituted Cu2O compositions for advanced applications

Cu2O based semiconductor materials are promising candidates for modern electronic devices due to have excellent electronic and optical properties. In this work, pure and Ag doped Cu2O structures were simulated using density functional theory in the framework of wien2k code with generalized-gradient-approximation under full potential linearized augmented plane wave approach. Experimentally, pure and Ag doped Cu2O uniform thin films were successfully fabricated. The morphology and elemental compositions of thin films were investigated using field emission scanning electron microscopy and energy dispersive x-rays spectroscopy, respectively. X-ray diffraction analysis exhibited cubic phase having space-group 224-Pn-3m in all synthesized thin films. Total density of states spectra for Ag containing compositions present overlapping of states at Fermi level. Thermoelectric properties show a significant variation in various parameters with the change in temperature and Ag content in structure. The see-beck coefficient was observed to vary from 0.0002 to 0.00035 Vk−1 for pure and Ag doped Cu2O compositions. The optical parameters like extinction and absorption curves attains maximum values at higher photon energies. The refractive index presents an enhanced transmittance power with the increment in photon energy. The band gap was found to reduce from 2.33 eV to 1.99 eV with Ag doping attributed to the sharp increase in optical conductivity.

Ab initio study of the newly proposed full Heusler alloy Co2CuAl : Insights from DFT

The Wien2k code is used to investigate the structural and electronic properties of Co2CuAl using tools of Density Functional Theory (DFT). In light of different exchange correlation potentials, we have obtained the information about optimized crystal structural, density of states (DOS), and band structure of possible non-magnetic and spin polarisation phases of this alloy. Structure optimization analysis revealed that the alloy is stable in the spin-polarised (SP) phase. Further the analysis of electronic DOS and band structure show the presence of anisotropic semi-metallic behaviour and indicate the potential of Co2CuAl to be a novel Heusler alloy.

Insight on structural, electronic and thermoelectric properties of perovskite AgBaCl3 by an Ab-initio for solar cell and renewable energy

The physical properties of the Ag-based perovskite compound AgBaCl3 has been studied utilizing FP-LAPW approach as embedded in WIEN2k code. The PBE-GGA approximation has been considered for the structural optimization. The structural and thermodynamical stability of the studied AgBaCl3 is confirmed from its tolerance factor, formation energy and cohesive energy. The band structure and density of states are estimated for electronic characteristics, proving the semiconductor nature, with indirect band gap values for PBE-GGA of 1.8 eV. The optical characteristics of the AgBaCl3 are studied in terms of the real and imaginary dielectric function, refractive index and reflectivity The thermoelectric properties of the compounds are studied at a temperature range of 0–1200 K with temperature. The high-power factor of the studied compound reveals its potential application in thermoelectric devices.

First principles and mean field study on the magnetocaloric effect of YFe3 and HoFe3 compounds

In this work, the magnetothermal characteristics and magnetocaloric effect in YFe3 and HoFe3 compounds are calculated as function of temperature and magnetic field. These properties were investigated using the two-sublattice mean field model and the first-principles DFT calculation using the WIEN2k code. The two-sublattice model of the mean-field theory was used to calculate the temperature and field-dependences of magnetization, magnetic heat capacity, magnetic entropy, and the isothermal change in entropy ∆Sm. We used the WIEN2k code to determine the elastic constants and, subsequently, the bulk and shear moduli, the Debye temperature, and the density-of-states at Ef. According to the Hill prediction, YFe3 has bulk and shear moduli of roughly 99.3 and 101.2 GPa respectively. The Debye temperature is ≈ 500 K, and the average sound speed is ≈ 4167 m/s. In fields up to 60 kOe and at temperatures up to and above the Curie point for both substances, the trapezoidal method was used to determine ∆Sm. For instance, the highest ∆Sm values for YFe3 and HoFe3 in 30 kOe are approximately 0.8 and 0.12 J/mol. K, respectively. For the Y and Ho systems, respectively, the adiabatic temperature change in a 3 T field decreases at a rate of around 1.3 and 0.4 K/T. The ferro (or ferrimagnetic) to paramagnetic phase change in these two compounds, as indicated by the temperature and field dependences of the magnetothermal and magnetocaloric properties, ∆Sm and ∆Tad, is a second-order phase transition. The Arrott plots and the universal curve for YFe3 were also calculated and their features give an additional support to the second order nature of the phase transition.

Study of structural, electronic, magnetic, and optical properties of A2FeMnO6 (A = Ba, La) double perovskites, experimental and DFT analysis

The electronic, magnetic, dielectric, and optical properties of double oxide perovskites A2FeMnO6 (A= Ba, La) are studied for spintronic and energy applications by experimental and theoretical routes. The hydrothermal process is used for sample preparation and modified Becke and Johnson potential through Wien2K code for simulation. The XRD and Rietveld refinement patterns confirm the cubic structure of Ba2FeMnO6 with space group Fm3̅m (No.225) and orthorhombic structure of La2FeMnO6 with space group Pbnm (No. 62). The SEM analysis of surface morphology shows particle size on average between 500 and 550 nm. The FTIR indicates the growth of functional bonding for wavelength 500–600 cm−1. The energy band gaps 1.47 eV and 1.18 eV are found by Touc plots which are suitable for optoelectronics. The dielectric constant, dielectric loss, and complex impedance of the samples were calculated. The impedance spectroscopy studies reveal the presence of orientational polarization in the samples at a low-frequency range. Moreover, theoretical calculations have been done by density functional theory and addressed the Half metallic ferromagnetism in A2FeMnO6(A= Ba, La). This ferromagnetism grows due to the exchange mechanism and hybridization of the electron's spin rather than the clustering effect. Finally, the optical properties are addressed by dielectric constants, and their dependence on parameters like absorption, refractive index, reflectivity, and optical loss.

Electronic, optical and thermoelectric properties of halide double perovskites Rb2AgInX6 (X = Cl, Br, I)

In the last decades, lead-based perovskites have been substantially investigated due to their superior efficiency in photovoltaics. However, owing to the harmful effect of lead, the search for other environmentally friendly materials is vital. Recently, halide double perovskites have gained attention due to their environmental friendliness and potential applications in solar cells and thermoelectric devices. The energy gap, optical and thermoelectric parameters of Rb2AgIn(Cl/Br/I)6 halide double perovskites compounds were investigated using Wien2k and BoltzTraP2 code based on DFT. The energy gap was 2.62 eV, 1.74, and 0.56 eV for Rb2AgIn(Cl/Br/I)6 at the Γ-points, which were direct bandgaps. More states were localized near the upper valence band, closer to the fermi energy, than near the lower conduction band, suggesting that Rb2AgIn(Cl/Br/I)6 was p-type. The fundamental edge of absorption arises at 2.48 eV, 1.67 eV, and 0.45 eV for Rb2AgIn(Cl/Br/I)6. The optical bandgaps calculated using the Tauc plot were 2.59 eV, 1.7 eV, and 0.49 eV for Rb2AgIn(Cl/Br/I)6. The first absorption band illustrates that these halide double perovskite compounds show high in the visible spectrum, with maximum absorption in the UV region. The Seebeck coefficient was positive, indicating the presence of p-type carriers. The calculated hole concentrations at room temperature were 3.08 × 1020 cm−3, 1.72 × 1020 cm−3, and 8.37 × 1019 cm−3 for Rb2AgInCl6, Rb2AgInBr6 and Rb2AgInI6 respectively. Large Seebeck coefficients with high thermoelectric efficiencies (greater than unity at room temperature) were observed for these halide double perovskites compounds.

Effect of substitution of 3d, 4d and 5d elements on structural, electronic, magnetic properties and XMCD spectra of Co-based full Heusler alloys: A DFT study

In the present work, we have probed the role of substitution of 3d, 4d and 5d elements (i.e., with electronic configuration (EC): ndy, where n = 3–5; y = number of electrons in the d level) at the B site on structural, magnetic and electronic properties of a set of full Heusler alloys (FHAs) namely, Co2BAl, using density functional theory (DFT) based electronic structure (ES) calculations. We have optimized all the 30 combinations studied here in Fm3̄m (A2BC type, conventional FHA structure) and F4̄3m (ABAC type, inverse FHA structure) space groups using VASP code. Thereafter, ES calculations have been carried out using DFT based FPLAPW method as implemented in WIEN2k code with an exchange-correlation term (PBE + mBJ + SOC), which is beyond GGA and includes the spin-orbit-coupling (SOC). Furthermore, XMCD calculations have been performed using single particle approximation and Fermi’s Golden rule as implemented in WIEN2k code. FHAs with atoms having EC nd1−6,10 (n = 3–5) at B site have Fm3̄m as the lowest energy structure with the exception of 4d6 and 5d6. Calculated magnetic moments (MM) of these alloys with atoms with EC nd1−5 are found to be in agreement with the Slater-Pauling (SP) rule, with an integer or close to integer value along with 3d6. However, alloys having atoms at B site with nd7−9 (along with 4d6 and 5d6) are found to be in F4̄3m space group and their values of the MM are not in agreement with the SP rule. XMCD spectra corresponding to various atomic sites help in understanding the impact of the local environment. Hence, calculations of the same have been performed to understand the low values of Co MM with atoms at B site having EC 3d3−5 and the negative MM of the Ti and Zr atoms at B site.

Improving thermodynamic properties and desorption temperature in MgH2 by doping Be: DFT study

ABSTRACT Storage of hydrogen is a necessary prerequisite for the commercialisation of hydrogen used in the production of energy. The solid-state storage of hydrogen is one of the many different methods for storing hydrogen, requiring much research. This work aims to optimise the desorption temperature and kinetic characteristics of MgH2 by introducing Be doping at varying concentrations using density functional theory within the WIEN2k code. Gravimetric hydrogen storage capacity increases as the Be concentration increases. Formation energy, cohesive energy and desorption temperature improve with the doping of Be. Elastic constants are then used to determine which hydrides are mechanically stable. All of the hydrides, except for MgBe3H8, meet the Born stability conditions, which means that they are mechanically stable. The bonding characteristics, shear modulus, bulk modulus, Cauchy pressures and Vicker’s hardness test are all measured and analysed. These hydrides can be classified as semiconductors based on their electronic properties, and bandgap values decrease with the concentration of Be. Many previously undiscovered thermodynamic features of these hydrides are examined and presented. The Seebeck coefficient, a figure of merit, and electrical and electronic-thermal conductivities are also calculated to investigate the thermoelectric properties.

Stability, electronic band structure, magnetic, optical and thermoelectric properties of CoXCrZ (X = Fe, Mn and Z = Al, Si) and FeMnCrSb quaternary Heusler

• The stability of these quaternary Heusler alloys has studied from the calculation of their cohesion energy. • The magnetization of these quaternary Heusler comes mainly from the 3d electrons of the Fe, Co, Mn and Cr atoms. In these materials, one spin has a finite density of states at the Fermi level, the other has a band gap. • The electronic structure of Heusler alloys depend on the degree of structural order and distribution of the atoms in the crystal lattice. CoFeCrAl, CoFeMnSi, CoMnCrSi, and FeMnCrSb Heusler alloys show SGS behavior with high Curie temperatures, thus making them suitable substitutes for diluted magnetic semi-conductors. • The increase in temperature for the spin up case reduces the figure of merit and increases the total electronic conductivity in these quaternary Heusler. • The resistivity of studied quaternary alloys is little sensitive to the temperature, while the electronic conductivity and power factor are proportional to the temperature. Ab-initio simulations based on density functional theory as contained in the WIEN2k code using GGA, GGA+U, and mBJ approximations were used to perform the calculations. The energy of cohesion is minimal for FeMnCrSb, indicating that it is the most stable structure, with a lattice constant of 5.95 Å and 6.2184 Å for GGA and GGA+U. The ferromagnetic state is less stable than ferrimagnetic states in all studied quaternary Heusler. All the band structures are metallic, with the exception of the spin up case using GGA+U and mBJ approaches, where the semiconducting character is predicted. The amount of absorption and band gap validate the candidature of CoFeCrAl, CoFeMnSi, CoMnCrSi, and FeMnCrSb as absorber materials for photovoltaic devices. The high values of 0.8, 0.9, 0.95 and 1 for figure of merit (ZT) at 300 K were obtained for CoFeMnSi, CoFeCrAl, CoMnCrSi, and FeMnCrSb allowing their use in spintronic and thermoelectric applications. The resistivity of studied quaternary alloys is little sensitive to the temperature, while the electronic conductivity and power factor are proportional to the temperature. Ferromagnetic (Ferro) and possible ferrimagnetic (Ferri) configurations of quaternary Heusler XX'YZ.

Theoretical validation of experimental properties of TiO2 prepared through organometallic precursors

Our TiO2 thin films were elaborated using spray pyrolysis technique. The spray solutions were prepared by two titanium precursors: titanium (IV) propoxide and titanium chloride. The elaborated thin films were analyzed with different characterization techniques such as X‐ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and UV–visible spectroscopy. These characterizations showed that the change of precursors from titanium chloride to titanium propoxide has a significant impact on all TiO2 properties. The structural characterizations showed the formation of anatase TiO2 and the crystallization improvement when the precursor changed from titanium chloride to titanium (IV) propoxide, which proves the superiority of our TiO2 thin layers made without any type of annealing in comparison with other previous studies. The SEM images showed an improvement of the surface quality of the TiO2 thin layers with the change of TiO2 precursors' solution. The obtained optical properties confirmed the semiconducting properties of TiO2 prepared by titanium propoxide with a large band gap equal to 3.28 eV and shifted to 3.18 eV. The refractive index increases from ~1.75 to ~2.14, while the porosity decreases. To confirm the experimental results, the Wien2K code, founded on the full‐potential linearized augmented plane wave (FP‐LAPW), has been used. The theoretical study has been done by applying the generalized gradient approximation (GGA), the modified Beck‐Johnson (MBJ) exchange potential, and the local spin density approximation + Hubbard's parameter U (LSDA + U). The theoretical results varied with the variation of approximations. The obtained properties were improved with LSDA + U and acquired the real values of Eg, n, and k for anatase TiO2 (like Eg = 3.214 eV). The obtained experimental and theoretical results could be considered superposable or better than other ones recently published.