First-Principles Calculations Of Structural, Electronic, And Optical Properties Of Spinel 〖Zn〗_2 MO_4 (M= Ti, Si, Pb)

First principle study of structural and optoelectronic properties of ZnLiX3 (X = Cl or F) perovskites

In this work, the structural, mechanical, electronic, optical and magnetic properties of the RhNbSb half‐Heusler compound were examined and analyzed using density functional theory (DFT). According to the results, type I atomic arrangement is structurally the most stable for the compound. In all three of its atomic arrangement types, the compound is mechanically stable and ductile according to the analysis of its mechanical properties. Generalized gradient approximation (GGA) + U approach was applied in addition to GGA approach, where U is Hubbard parameter, to increase the accuracy of results in electronic band structure, density of states (DOS), and magnetic moments. Therefore, electronic band structure and DOS calculations demonstrate that the compound exhibits metallic properties in both its type I and type II atomic arrangements with GGA predictions. However, under GGA + U calculations, the compound becomes half metal when in type I but it still reflects metallic nature when in type II. The compound’s half‐metallic nature in type I under the GGA+U method suggests that it may be a good fit for spintronics applications in this type I of its atomic arrangement. The calculated total magnetic moment of the compound under GGA + U approach exactly fits with Slater–Pauling rule of half‐metallic nature in its type I atomic arrangement, a result that supports half‐metallic nature of the compound in type I atomic arrangement for electronic properties under GGA + U prediction. Furthermore, the compound might be taken into consideration for optoelectronic applications according to the results of computed optical characteristics.

Comprehensive analysis of the structural, elastic, electronic, optical, and mechanical properties of orthorhombic CS(NH2)2 under pressure: A first-principles approach

The structural, electronic, optical, mechanical and vibrational properties of hexagonal Di-Tellurium-Tungsten (Te2W) are exploited with a hybrid Heyd–Scuseria–Ernzerhof 2003 (HSE03) functional and semi-local general gradient approximation (GGA) scheme using ab initio density functional theory (DFT) calculations. The structural and electronic properties have been analyzed with the band structure and electron orbitals from the partial density of states (PDOS). Our reflectivity data from optical spectra explain its applications over mechanical engineering such as lubricant oils, further with the fact that the refractive index results obtained suggest the possibility of deploying Te2W material over optical displays. Our work finalizes by testifying the physical and mechanical stability, with our DFT-calculated elastic coefficients along with its criteria, mechanical moduli and phonon data provided. In general, our non-local hybrid functional corrects the band structure and bandgap energy [Formula: see text] extremely well, over the traditional semi-local exchange-correlation functional.

In this present study, electronic, mechanical, thermodynamic and optical properties of RaHfO₃ crystal were investigated by Generalized Gradient Approximation (GGA) based on PBE, RPBE, and PBEsol and hybrid B3LYP methods. The calculated bandgap energies (Eg​) of RaHfO₃ were found to be 2.247 eV, 2.178 eV, 2.095 eV, and 3.520 eV, as determined using the PBE, RPBE, PBEsol, and B3LYP approaches, respectively. The atomic orbital properties of Ra, Hf, and O in RaHfO3 were analyzed through total and partial density of states (DOS) analysis. Mulliken population charge analysis provided insights into the bonding characteristics of the RaHfO3 crystal. Mechanical stability was verified using the Born stability criterion, and Poisson’s ratio and Pugh’s ratio were evaluated to assess ductile strength and elastic anisotropy. To find out the material's thermodynamic stability and state behavior, thermophysical factors were seized at. The RaHfO3 crystal demonstrates both mechanical and thermal stability, along with ductile behavior and elastic anisotropy. Its optical properties were thoroughly evaluated focusing on energy and wavelength, both approaches confirmed that RaHfO3 exhibits remarkable absorption in the visible and ultraviolet regions. These outstanding properties suggest that RaHfO3 could be a promising candidate for photocatalytic applications, demonstrating efficient responsiveness to visible light.

Recently, a new 2D carbon allotrope named biphenylene network (BPN) was experimentally realized. Here, we use density functional theory (DFT) calculations to study its boron nitride analogue sheet's structural, electronic, and optical properties (BN-BPN). Results suggest that BN-BPN has good structural and dynamic stabilities. It also has a direct bandgap of 4.5 eV and significant optical activity in the ultraviolet range. BN-BPN Young's modulus varies between 234.4[Formula: see text]273.2 GPa depending on the strain direction. Density functional theory (DFT) simulations for the electronic and optical properties of BN-BPN were performed using the CASTEP package within the Biovia Materials Studio software. The exchange and correlation functions are treated within the generalized gradient approximation (GGA) as parameterized by Perdew-Burke-Ernzerhof (PBE) and the hybrid functional Heyd-Scuseria-Ernzerhof (HSE06). For convenience, the mechanical properties were carried out using the DFT approach implemented in the SIESTA code, also within the scope of the GGA/PBE method. We used the double-zeta plus polarization (DZP) for the basis set in these cases. Moreover, the norm-conserving Troullier-Martins pseudopotential was employed to describe the core electrons.

The electronic and optical properties of NaSrX3 (X = Br, I) perovskites using density functional theory (DFT) with GGA (Generalized Gradient Approximation) formalism. The lattice parameters obtained are 5.22 Å and 5.74 Å for NaSrBr3 and NaSrI3, respectively. NaSrBr3 and NaSrI3 have direct gaps of 2.51 eV and 1.49 eV, respectively. They all have a conduction band dominated by 3d statesof Sr, weakly mixed with 3s states of Na and 4s states of Sr. The valence band is dominated by the 2p states of the alkali metal and the 3d states of Sr. These perovskites also have very good optical properties: low reflectivity and high absorption in the ultraviolet. Observation of the different optical functions shows that the materials can slow down and deflect light in both the visible and ultraviolet ranges. Light can also be absorbed in energy ranges corresponding to the visible and UV spectrums. They are also transparent between 10 eV and 20 eV. These materials are suitable for various applications in both the visible and UV spectrums. The elastic properties of NaSrBr3 and NaSrI3 are also very interesting. The elastic constants found verify the criteria for mechanical stability. NaSrBr3 and NaSrI3 are ductile and likely to be ionic. They are anisotropic and stable materials. NaSrBr3 has a higher melting point than NaSrI3. This work confirms that NaSrBr3 and NaSrI3 have very good electronic, optoelectronic, elastic, and optical properties. Their use in a photovoltaic cell could increase its conversion efficiency.

Boron-rich chalcogenides have been predicted to have excellent properties for optical and mechanical applications in recent times. In this regard, we report the electronic, optical, and mechanical properties of recently synthesized boron-rich chalcogenide compounds B12X (X = S and Se) using density functional theory for the first time. The effects of exchange and correlation functionals on these properties are also investigated. The consistency of the obtained crystal structure with the reported experimental results has been checked in terms of lattice parameters. The considered materials are mechanically stable, brittle, and elastically anisotropic. Furthermore, the elastic moduli and hardness parameters are calculated, which show that B12S can be treated as a prominent member of the hard materials family compared to B12Se. The origin of differences in hardness is explained on the basis of density of states near the Fermi level. Reasonably good values of fracture toughness and the machinability index for B12X (X = S and Se) are reported. The melting point, Tm, for the B12S and B12Se compounds suggests that both solids are stable, at least up to 4208 and 3577 K, respectively. Indirect band gaps of B12S (2.27 eV) and B12Se (1.30 eV) are obtained using the HSE06 functional. The energy gaps using local density approximation (LDA) and generalized gradient approximation (GGA) are found to be significantly lower. The electrons of the B12Se compound show a lighter average effective mass than that of the B12S compound, which signifies a higher mobility of charge carriers in B12Se. The optical properties such as the dielectric function, refractive index, absorption coefficient, reflectivity, and loss function are characterized using GGA-PBE and HSE06 methods and discussed in detail. These compounds possess bulk optical anisotropy, and excellent absorption coefficients in the visible-light region along with very low static values of reflectivity spectra (range of 7.42–14.0% using both functionals) are noted. Such useful features of the compounds under investigation show promise for applications in optoelectronic and mechanical sectors.

In this study, density functional theory calculations were used to investigate the structural, electronic, mechanical, and optical properties of SrAlO3 perovskites. Calculations were performed using WEIN2K with the Generalized Gradient Approximation (GGA) and modified Becke-Johnson (MBJ) methods. The present compound shows large band gap around 5.67 eV for GGA method and 6.70 eV for MBJ method. The band structure (BS) and partial density of states (PDOS) reveal the predominant involvement of the oxygen-p orbital in the valence band, while the Al and Sr-s, p and d orbital contribute significantly to the conduction band, that play a significant role in determining the electronic and optical properties. Using the GGA and MBJ methods, the optical properties of SrAlO3 have been determined in terms of optical conductivity, dielectric constant, absorption coefficient, energy loss, optical reflectivity, and refractive index. It has been noted that the features present in the optical absorption spectra obtained experimentally match those of the simulated spectra featuring an oxygen vacancy. We use elastic constants to describe a material's mechanical properties. Under normal conditions, these materials' elastic constants demonstrate their mechanical stability. We meticulously determined the elastic constants by graphing the directional variations of compressibility, Young's modulus, and shear modulus. Our findings indicate that these chemicals have high elastic constants. Furthermore, we collect and interpret the phonon spectra. Complete phonon dispersion simulations validate the dynamic stability of the SrAlO3.

Doped BaZrO3 is well recognized as a promising material for proton conduction, particularly in solid oxide fuel cells (SOFCs) and various electrochemical applications. While this material has been thoroughly examined for proton conduction, it has not been as extensively studied for other potential applications, such as photocatalytic water splitting and solar cell devices. This investigation delves into the comprehensive assessment of structural, electronic, optical, mechanical, and thermodynamic properties in Ti-doped BaZrO3 (BaZr1-xTixO3 where x = 0,0.25, 0.5, 0.75) through the application of Density Functional Theory (DFT) employing the Generalized Gradient Approximation (GGA) and Perdew-Burke-Ernzerhof (PBE) exchange-correlation function. After doping, all of the doped compounds undergo a phase transition from cubic to tetragonal once Ti is added to BaZrO3. Analysis of the computed structural properties reveals a slight reduction in lattice parameters accompanied by a decrease in cell volume. The doping of Ti led to a reduction in the electronic bandgap energy of BaZrO3. Specifically, the bandgap decreased from an initial value of 3.118eV at x = 0, which was an indirect bandgap, to a lowest value of 1.8eV at x = 0.5, also identified as an indirect bandgap. This bandgap reduction leads to significant changes in optical properties, enabling absorption at lower photon energies compared to pure BaZrO3, which is beneficial for photocatalytic water splitting and solar cell applications. Mechanical properties confirmed the stability of the investigated composition through the Born stability criteria. Furthermore, thermodynamic properties across different doping concentrations revealed the highest Debye temperature at x = 0.75, indicating a higher melting point and enhanced thermal stability.

An extensive study of structural, electronic, optical, mechanical, and thermodynamic properties of inorganic oxide perovskite materials ScXO3 (X = Ga, In) for optoelectronic applications: A DFT study

This study examined the structural, electronic, optical, mechanical, and thermal properties of K-based halide perovskites KGeX3 (X = Cl, Br). All the calculations have been carried out using the DFT-based CASTEP simulation package with an ultra-soft pseudo-potential plane wave and PBE-GGA technique. Both the studied perovskite compounds are stable in terms of mechanical and thermal stability. The calculated electronic properties indicate that both materials have a semiconducting behavior with a direct band gap. The band gap value is 0.92 and 0.62 eV for KGeCl3 and KGeBr3, respectively. The analysis of the electronic properties reveals a notable reduction in the bandgap as chlorine (Cl) is substituted with bromine (Br), decreasing from 0.92 to 0.52 eV. The results of our calculations are in good agreement with the previously reported research. The optical properties analysis reveals that both materials demonstrate high absorption and minimal reflection within the visible spectrum. The determined values for Poisson’s and Pugh’s ratios suggest that studied materials demonstrate a ductile behavior. The obtained values of Debye temperature are 265.25 and 191.62 K for KGeCl3 and KGeBr3, respectively. Based on their appropriate direct band gap and high absorption coefficient, these materials are considered promising candidates for photovoltaic applications, and are proposed as ideal potential materials for solar cells applications.

In the renewable industry, pressure-dependent CsPbBr3 perovskite has a lot of potential due to its exceptional properties. Present work revealed the mechanical stability of CsPbBr3 between 0 to 50GPa. The bandgap of unstressed CsPbBr3 is 2.90eV, indicating a direct bandgap. Band gap values decrease by increasing external pressure. CsPbBr3 structure showed a direct band gap from 0 to 35GPa and in-direct from 40 to 50GPa. The unit cell volume and lattice constants are substantially decreased. Mechanical parameters, i.e., Young's modulus, bulk modulus, anisotropy factor, shear modulus, and poison's ratio are obtained. Under ambient conditions, the mechanical properties of CsPbBr3 showed ductile behavior and with induced pressure, their ductility has significantly improved. By applying stresses ranging from 0 to 50GPa, the considerable fluctuation in values of dielectric function (imaginary and real), absorption, reflectivity, loss function, refractive index (imaginary and real), and conductivity (imaginary and real), was also identified. When pressure rises, the optical parameters increase and drag in the direction of high energies. Response functions are used to predict the density of states and the phonon lattice dispersion to study the phonon properties. By using the quasi-harmonic Debye model, the thermal effect on the free energy, entropy, enthalpy, and heat capacity were predicted and compared. These results would be useful for theoretical research and indicate how external pressure significantly affects the physical characteristics of CsPbBr3 perovskites, which may open up new possibilities for use in optoelectronic, photonic, and solar cell applications. The structural, electrical, mechanical, optical, and thermal properties of cesium lead bromide (CsPbBr3) are investigated by applying external pressure from 0 to 50GPa, using generalized gradient approximations (GGA) and Perdew-Burke-Ernzerhof (PBE) with CASTEP code built-in material studio by density functional theory (DFT).

The structural, elastic, electronic, magnetic and optical properties of SrNiO3 perovskite: A DFT and DFT+U study

Structural, electronic and magnetic properties of inverse spinel NiFe2O4: DFT + U investigation