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Doping techniques are commonly utilized to effectively modify the physical properties of a desired compound. In this study, we employed the first-principles DFT calculations with a GGA + TB-mBJ approach as implemented by the Wien2k code, by investigating the effects of oxygen group element concentrations on the structural, electronic, and optical properties of the perovskite substance SrTiO 3. We calculated the formation energies of each doped structure to assess the viability of synthesis. The band gap is equal to 1.355 eV, 0.653 eV, and 0.632 eV for 12.5 % S, Se, and Te doped SrTiO 3 , respectively. For the pure SrTiO 3 , the band gap is 2.584 eV. According to our findings, raising the chalcogen concentrations resulted in a considerable decrease in band gaps and an improvement in the ability to absorb light in the visible range (380–790 nm), exceeding 105 cm−1 for Te doped SrTiO 3 (STO). At zero frequency, the dielectric constant was found (ε1 (0)) to be 4.432 for SrTiO 3 pure and 6.332 for SrTiO 3 doped with Te (12.5 %) in GGA-PBE and (ε 1 (0)) = 4.432 and 12.217 for GGA + mBJ. The optical conductivity of SrTO 3 doped with Te is determined to be 0.322 * 104 /Ω. cm , in comparison to a value of 0.377 * 104/Ω. cm for mBJ. Our research revealed that raising the chalcogen concentrations significantly enhanced the electrical conductivity, as predicted, along with improvements in optical conductivity and reflectivity. SrTiO 3-x Y x (Y = S, Se, or Te) represents one of our quaternary alloys, demonstrating substantial potential as a promising material for advanced photovoltaic and solar cell applications. Our findings revealed that the doped materials exhibited significantly high absorption rates and productivity. We also examined additional optical parameters, including optical band gap, Urbach energy, and optical conductivity. [ABSTRACT FROM AUTHOR]

The structural, electronic, magnetic, magnetocaloric, and thermoelectric properties of the SrXO3 (X = Mn and Fe) perovskite compounds were investigated using first-principles calculations. It was observed that the SrXO3 compounds are G-anti-ferromagnetic perovskites with partial magnetic moment with a value of 2.7 μ B and 2.4 μ B for Mn-3d and Fe-3d orbitals for SrMnO3 and SrFeO3, respectively. Moreover, by using Monte Carlo simulation (MCs) combined with the Metropolis algorithm, the calculated coupling interactions between the magnetic atoms Mn–Mn and Fe–Fe are J 1 Mn = 5. 1 7 meV and J 2 Mn = − 0. 6 meV for SrMnO3, J 1 Fe = 3. 4 4 meV and J 1 Fe = − 0. 4 meV for SrFeO3, respectively. Furthermore, a significant magnetocaloric effect (MCE) was observed around the Néel temperature of T N Mn = 2 6 0 K (for SrMnO3) and T N Fe = 1 3 4 K (for SrFeO3), and the maximal simulated magnetic entropy and relative cooling power values of all the studied compounds are found to be 100 J/kg (for SrMnO3) and 110 J/kg (for SrFeO3), respectively, with an applied magnetic field of H = 4. 0 T. These results are in complete agreement with the experimental results and more specifics than other theoretical calculations. Hence, SrXO3 compounds are considered promising candidates for magnetic refrigeration at low temperature. [ABSTRACT FROM AUTHOR]

The electronic and thermoelectric properties of the perovskite LaCoO3 compound were studied using first-principles calculations. However, Monte Carlo calculation (MC) combined with the Metropolis algorithm, calculates the magnetic and magneto-caloric properties. The partial moment of the Cobalt atom (Co) and exchange coupling interactions for Co-d orbital at high spin (HS: S = 2), show values µCo = 2.54${\rm \mu }_{B\; \comma }J_1^{{\rm Co}-{\rm Co}} = 2.39\; {\rm meV} \comma \; J_2^{{\rm Co}-{\rm Co}} = 0.9\; {\rm meV}\comma$μB,J1Co−Co=2.39meV,J2Co−Co=0.9meV, respectively. The calculated Curie temperature value (TC) is 100 K, which agrees with the experimental results, such as the LaCoO3 metallic perovskite has a secondary Ferro-Para magnetic transition around TC. The evolutions in magnetic and magnetocaloric (MEC) properties with external magnetic fields were also studied. Finally, thermoelectric properties are examined. [ABSTRACT FROM AUTHOR]

One of the most important areas of materials science research is the creation of novel materials for energy conversion and storage. Computational simulations have become a potent tool for anticipating novel material characteristics and speeding up the discovery process in recent years. In this article, we present a computational investigation of the structural, electronic, and optical properties of double perovskites Cs 2 KInX 6 (X = Br, Cl, and I), with a focus on their potential applications in energy conversion. The purpose of this work is to accomplish a comparative analysis of novel optoelectronic lead-free halide double perovskites. The Cs 2 KInX 6 double perovskites compounds display direct semiconducting behavior with optical bandgap energies values of about 2.60, 3.60, and 1.67 eV for Cs 2 KInBr 6 , Cs 2 KInCl 6 , and Cs 2 KInI 6 , respectively. The results obtained underscore the remarkable characteristics of the studied compounds. Notably, a substantial absorption coefficient exceeding 106 cm−1 in the ultraviolet range and a notable absorption coefficient surpassing 105 cm−1 in the visible spectrum were observed. The obtained optoelectronic characteristics that have been indicate that Cs 2 KInX 6 compounds hold great potential for usage in solar cell applications. [ABSTRACT FROM AUTHOR]

In this paper, we examine the impact of vehicles executing a full turn or U-turn in a single-lane roundabout system using a cellular automaton model. We investigate how increasing the number of these U-turning vehicles affects traffic flow characteristics and energy dissipation. Our findings reveal that as the prevalence of U-turning vehicles rises, the phase diagram undergoes significant changes; the maximum current phase expands, detrimentally impacting the free flow and congestion phases, while giving rise to a jamming phase. This shift results in a gradual increase in capacity at circulating lanes and a steady decline at entry/exit lanes. We also explore the role of aimless vehicles — those circulating without a fixed destination. As the proportion of such vehicles augments, it fosters an enlargement of the maximum current phase at the expense of the free flow and congestion phases. Furthermore, these vehicles influence energy dissipation across the three lanes of a roundabout. Significantly, we elucidate that variations in the percentage of these specific vehicular groups critically affect CO2 emissions. Our research unravels vital insights into optimizing roundabout management to enhance traffic flow and reduce environmental impact. [ABSTRACT FROM AUTHOR]

Researchers are working on perovskites for photovoltaic applications due to their low cost and excellent power conversion efficiency. Our investigation has focused on analyzing the effects of hydrostatic strain on the structural, electronic, optical and thermoelectric properties of CsSnBr3. The calculated structural properties and enthalpy of formation imply that these structures are stable under different strain conditions. Our investigation shows that the CsSnBr3 compound is a direct semiconductor with an electronic band gap of 1.272 eV, which can be tuned from 0.604 eV to 1.823 eV under different strain conditions. As the compressive strain increases, the light absorption spectrum of CsSnBr3 undergoes a red shift, causing a prolongation of the light absorption edge. The thermoelectric properties show that CsSnBr3 is a p-type semiconductor. Our findings indicate that the CsSnBr3 material is highly suitable for photovoltaic applications. [ABSTRACT FROM AUTHOR]

Novel Sillenites Bi25Fe(1−x)AlxO40 (x = 0.00, 0.20, and x = 0.50) have been synthesized using the SSR method. In this paper, the effect of Al-substitution on the physicochemical properties was performed. The X-ray diffraction analysis as well as both Raman and FT-IR spectroscopies indicate that all the elaborated materials have a bcc structure with the I23 space group. The increase of the cell parameters, the morphological features, and thus the decrease of the grain size with Aluminum content is also evidenced via the X-ray patterns and SEM microscopy. DSC measurements highlighted the occurrence of various phenomena related to both structural and dielectric features. The temperature dependence of electrical conductivity and the deduced activation energies pointed to the effect of temperature on the conduction process. The impedance analysis on the samples confirms the onset of relaxation phenomenon in the sample with semiconducting behavior. Furthermore, an AFM-Paramagnetic transition for x = 0.00 and 0.20, with Neel temperatures of 268 and 265 K, respectively. Otherwise, paramagnetic behavior is observed for x = 0.50. The optical measurements make these materials suitable candidates for photocatalysis and optoelectronic applications. [ABSTRACT FROM AUTHOR]

The manuscript explores the electromagnetic and magnetocaloric characteristics of the intermetallic compound Gd 2 Cu 2 C d. One of the key findings is that Gd2Cu2Cd possesses a magnetic moment of approximately 7.13 μB. The simulated magnetic properties illustrate a second-order phase transition from ferromagnetic (FM) to paramagnetic (PM) occurring at approximately 130 K. This material exhibits a substantial magnetocaloric effect (MCE) across various external magnetic field strengths. To be more specific, this transition occurs at an external magnetic field of 4.0 T, in particular, at an external magnetic field of 4.0 T, the extreme magnetic entropy change ( Δ S mag ) is measured at 3.58 J/kg.K, and the relative cooling power (RCP) reaches 28 J/kg. Notably, with an increase in the external magnetic field, the maximum value of ( ΔS mag ) increases significantly, and the Curie temperature ( T C ) shifts toward lower temperatures. These results suggest that Gd 2 Cu 2 Cd has significant potential for applications in magnetic refrigeration that leverage the magnetocaloric effect. [ABSTRACT FROM AUTHOR]

The main objective of many researches is to find an excellent reversible material for hydrogen storage applications under ambient conditions. The hydrogen adsorption on pure C 2 N-h2D shows an attractive result using density functional theory (DFT) calculations implemented with the van der Waals corrections, and ab-initio molecular dynamics (AIMD). A high adsorption energy up to - 0.3150 eV, the adsorption occurs through physisorption and no chemical bond is formed between the molecule and the C 2 N surface irrespective of the site of interaction, the migration process of H 2 molecule on the substrate was so easy due to the low activation energy which was found around 7.08 meV. The study shows large gravimetric capacity as well as volumetric capacity around 11.62 wt% and 117.20 g/l. Compared to the critical point of hydrogen (33.25 K), the desorption temperature (T D) was found to be around 229.23 K, which is considerably higher. The adsorption of 30H 2 molecules on C 2 N-h2D and the stability of the system was verified through AIMD simulations. Therefore, our material proved to be a promising candidate for hydrogen storage applications at room temperature. • The adsorption energy is around - 0.2849eV. • The gravimetric capacity up to 11.62 wt%. • The desorption temperature up to 229.23 K. • The activation energy about 7.08 meV. [ABSTRACT FROM AUTHOR]

Herein, the ground-state properties of the intermetallic compound NdPd and its magnetic observable curves as well as its magnetocaloric properties have been investigated using a combined Monte Carlo simulation and ab initio calculations. The calculated magnetic moment of Nd atom is 3.11 μB which is in agreement with the experimental one. Furthermore, it was established that the first two exchange couplings for Nd-Nd interactions present positive signs ( J 1 = 1.593 meV and J 2 = 0.358 meV), where both correspond to ferromagnetic interactions. In good agreement with recent experimental works, the simulation results revealed that the NdPd compound orders ferromagnetically at T c =16 K. It was moreover found that the isothermal magnetic entropy around the Curie temperature and the relative cooling power (RCP) in an applied magnetic field of 5 T are acceptable concurrence with those obtained in the laboratory. Besides, the good magnetocaloric properties of NdPd obtained here are quite convincing to predict that NdPd-based magnetic refrigeration can be considered a promising technology for cryogenic cooling systems within the range T < 20 K. [ABSTRACT FROM AUTHOR]

The manuscript explores the electromagnetic and magnetocaloric characteristics of the intermetallic compound Gd 2 Cu 2 C d. One of the key findings is that Gd2Cu2Cd possesses a magnetic moment of approximately 7.13 μB. The simulated magnetic properties illustrate a second-order phase transition from ferromagnetic (FM) to paramagnetic (PM) occurring at approximately 130 K. This material exhibits a substantial magnetocaloric effect (MCE) across various external magnetic field strengths. To be more specific, this transition occurs at an external magnetic field of 4.0 T, in particular, at an external magnetic field of 4.0 T, the extreme magnetic entropy change ( Δ S mag ) is measured at 3.58 J/kg.K, and the relative cooling power (RCP) reaches 28 J/kg. Notably, with an increase in the external magnetic field, the maximum value of ( ΔS mag ) increases significantly, and the Curie temperature ( T C ) shifts toward lower temperatures. These results suggest that Gd 2 Cu 2 Cd has significant potential for applications in magnetic refrigeration that leverage the magnetocaloric effect. [ABSTRACT FROM AUTHOR]

• Structural, electronic, optical, and photocatalytic characteristics of Cs 2 SnX 6 (X = Cl, Br, I) are investigated. • Density of states and band structure of Cs 2 SnX 6 (X = Cl, Br, I) has a direct band gap. • These compounds have strong optical absorption in the UV region. • The ideal band gap, low effective mass and optimal light absorption of Cs 2 SnI 6 make it suitable for photovoltaic applications. • Photocatalytic properties show Cs 2 SnBr 6 has a potential candidate for photocatalytic applications. In recent years, unique double perovskites have been increasingly used in solar cells and photocatalytic applications due to their stable structure and high energy conversion efficiency. Utilizing density functional theory, we investigated the structural, electronic, optical, and photocatalytic characteristics of the inorganic cubic halide perovskite Cs 2 SnX 6 (X = Cl, Br, I) with the aim of potential applications in diverse fields. The computed values of the lattice parameters match perfectly with the experimental and theoretical data. The formation enthalpy confirms the thermodynamic stability of this system. Using the GGA + mBJ method, predictions were made for suitable semiconductor direct bandgaps of 3.912 eV, 2.625 eV, and 0.863 eV for the perovskite materials Cs 2 SnCl 6 , Cs 2 SnBr 6 , and Cs 2 SnI 6 , respectively. For bandgaps, they decreased as Cl is replaced with Br and I, respectively suggesting improved solar cell performance. These three compounds have strong optical absorption in the UV region, and the absorption spectra red shift as the amount of halogen atoms increases. The ideal band gap, low effective mass, high exciton Bohr radius, and optimal light absorption of Cs 2 SnI 6 make it suitable for photovoltaic applications. Finally, the valence band maximum (VBM) and conduction band minimum (CBM) calculated values show that Cs 2 SnBr 6 can be a potential candidate for photocatalytic application. Using computational methodologies, this study can also provide theoretical advice for the rational design of new double perovskite materials with better photocatalytic features. [ABSTRACT FROM AUTHOR]

This comparative Monte Carlo study compares the magnetic properties of β₁₂, χ₃, and striped Borophene structures to reveal differences in magnetization, susceptibility, blocking temperature, and coercive field for each lattice. Beyond merely exploring these properties, the study delves into the crucial influence of exchange coupling (J) and external magnetic field (H) on both blocking temperature and hysteresis cycles. The research sheds light on how the intricate geometry of 2D Borophene materials plays a pivotal role in shaping their magnetic responses. This emphasizes the broader significance of geometric considerations.This multifaceted analysis provides insights into the interplay between structural features and magnetic behaviors, advancing the utilization of Borophene for magnetic applications. [ABSTRACT FROM AUTHOR]

In this work, the impact of triaxial strain on the structural, optoelectronic and mechanical properties of CsGeI₂Br is thoroughly investigated, with a particular emphasis on its applicability in optical technologies spanning the visible and ultraviolet spectra. This research fills a notable gap in the literature, highlighting the intriguing properties of this material under external strain. First, the unstrained CsGeI₂Br is identified as a direct band gap semiconductor, revealing an energy gap of 0.714 eV. Moreover, the obtained results show a remarkable sensitivity of CsGeI₂Br's band gap to triaxial strain. Under a triaxial deformation ranging from −6% to 6 %, the energy of the bandgap undergoes a remarkable transformation, varying from 1.81 eV under tensile stress to 0.101 eV under compressive strain; The material approaches the metallic state under compressive strain and exhibits increased bandgap energy under tensile stress. Furthermore, the investigation delves into the optical coefficients in both x = y, z directions, revealing that triaxial strain can significantly enhance absorbance, particularly within the visible and ultraviolet energy spectra. Additionally, triaxial strain introduces significant anisotropy and influences the optical band gap. This results in increased absorption capacity and optical conductivity under tensile stress, making it more effective and better suited for various optical applications, including surgical tools, integrated circuits, QLED, OLED, solar cells, waveguides, and materials for solar heat reduction. The mechanical stability of CsGeI₂Br across the entire range of applied strain is validated by the elastic constants, which impeccably adhere to stability criteria. The negative cohesive energy values determined for unconstrained and constrained CsGeI₂Br signify their thermodynamic stability, establishing their experimental feasibility. Compression strain significantly influences the mechanical properties, enhancing the ductility of this compound. • CsGeI₂Br stable under triaxial strains. • Improved absorption/optical conductivity. • Promising for photovoltaic/optoelectronic. [ABSTRACT FROM AUTHOR]