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In this investigation, we employ density functional theory with the generalized gradient approximation of Wu–Cohen and the modified Beck–Johnson approach. Our focus is on examining the structural, electronic and thermodynamic properties of ternary chalcopyrite CdXP2 (X: Si and Sn) compounds. Our computed results of ternary structures for structural properties, for instance, tetragonal distortion, equilibrium lattice constants and bond lengths, show good agreement with the available results of the experimental and theoretical calculations. Our calculated positive results of cohesive energy and negative values of the formation energies of the title materials show their thermodynamic stability as well as highlight their possible experimental fabrication at these concentrations. From band structure calculations, it is found that the energy bandgap is of direct nature at Γ–Γ symmetry points for both ternary and quaternary alloys; however, the width of the bandgap is found to be decreased with increasing Sn concentration in the CdSi1–xSnxP2 alloys. Moreover, thermodynamic properties using the quasi-harmonic Debye model are also computed. Our study provides a platform for further experimental and theoretical investigations to expose the potential of these materials for their applications. [ABSTRACT FROM AUTHOR]

Context: The present study reports the properties of pressure-induced phase transition, electronic and optical of phosphides XSiP2 under pressure in chalcopyrite, sodium chloride (rock salt), and Wurtzite phases. The study shows the chalcopyrite phase as the most stable phase among the other studied phases. The obtained structural parameters in the chalcopyrite and rock-salt phases reasonably agree with the literature. The computed band structures revealed a semiconductor behavior in chalcopyrite structure and metallic behavior for rock- salt and wurtzite structures. In the energy range of 0 to 30 eV, optical parameters such as the real and imaginary parts of the dielectric constant, refractive index, and reflectivity are calculated and compared with existing data. Our optical properties findings are predictive for the rock-salt and wurtzite phases. Since no results are available in the literature, these results may serve as references for other theoretical and experimental studies. Method: The calculations are performed by employing the "full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT)." [ABSTRACT FROM AUTHOR]

This research explored the physical properties of AuMTe2 (M = Ga, In) chalcopyrite compound. We employ the full-potential linearized augmented plane wave (FP-LAPW) method in combination with the Tran-Blaha modified Becke–Johnson potential (TB-mBJ) as well as the generalized gradient approximation (GGA-PBE(96)), local density approximation (LDA) and Wu–Cohen generalized gradient approximation (WC-GGA) for the exchange–correlation potentials to analyze the structural, electronic and optical properties. The results are presented for lattice constant, bulk modulus, its pressure derivative, density of state (DOS) and optical properties. The structural and electronic outcomes obtained in this study align well with existing theoretical data. Our investigation revealed that the studied compounds exhibit a direct band gap, with average energy gaps of order of 0.281 eV for AuGaTe2 and 0.092 eV for AuInTe2 compounds, respectively. Optical properties, encompassing reflectivity R(w), absorption coefficient α(ω), refractive index n(ω), optical conductivity σ(ω), extinction coefficient k(ω) and energy loss function L(ω) are determined from real and imaginary parts of the computed dielectric function within the frameworks of the modified Becke–Johnson plus PBE-GGA(96), LDA and WC-GGA exchange–correlation potentials. The computed optical properties reveal minimal energy loss and reflectivity, alongside satisfactory absorption capability and optical conductivity within the infrared and visible spectral regions. These findings indicate potential applications in fields such as infrared absorption technologies and optoelectronic industries. This marks the initial quantitative theoretical forecast of the optical properties for these chalcopyrite compounds, necessitating experimental confirmation. [ABSTRACT FROM AUTHOR]

A theoretical study was conducted to analyze electronic, elastic, and thermodynamic properties and the structural stability of the intermetallic materials Al3Ti1−xZrx for tetragonal-D022 and cubic-L12 structures carried out based on DFT. The findings indicate that the D022 phase has demonstrated more stability than the L12 phase and the possibility of a structural phase transition under pressure effect for concentrations x = 0.25 and x = 0.5. With increasing x concentration, the resulting lattice parameters drop. The density of states at the Fermi level, determines the electronic stability exhibited by these compounds. A pseudo-gap in proximity to the Fermi level implies the establishment of directional covalent bonding. The electronic structures support the phase stability results and show that the bonding in these compounds is more directed. Measurement techniques are employed to determine the number of bonding electrons per atom and the coefficient of electronic-specific heat. Both the mechanical as well as elastic properties of the considered alloys are examined. The findings demonstrate that all explored alloys are brittle, and D022 phase is stiffer than the L12 phase. The thermal characteristics are predicted via the quasi-harmonic Debye model. [ABSTRACT FROM AUTHOR]

In the present work, we present a theoretical study of the physical properties of ternary CdXP2 (X: Si, Ge, and Sn) chalcopyrite materials through the full-potential linearized augmented plane wave method. The generalized gradient approximations of Perdew, Burke, and Ernzerhof have been used to handle the exchange–correlation potential. Moreover, the electronic structure calculations are further improved through the modified Becke Johnson potential. Our calculations for the structural parameters of the studied compounds are found well-matching with the literature. Investigations of the electronic properties of the considered compounds have been executed through the calculation of the band structure. We observe that our compounds are semiconductors characterized by a direct energy gap between the Γ-Γ symmetry points. The optical constants, including the dielectric functions, were calculated for energy up to 30 eV. Using the GIBBS program, which is based on the quasi-harmonic model of Debye, we have investigated the thermodynamic behavior of the considered chalcopyrite under pressure and temperature effects. The variation of the volume, bulk modulus, and temperature-dependent Debye temperature and heat capacities for different pressures are estimated. [ABSTRACT FROM AUTHOR]

Knowledge of the physical properties of a material is crucial to realising its practical technological applications. In this regard, a study related to phase stability, transition pressure, electronic properties, optical properties, and thermal properties of GaAs, GaN, as well as their mixed ternary alloys GaN0.25As0.75, GaN0.5As0.5 and GaN0.75As0.25 is presented. The study is performed by employing a “full-potential-linearized augmented plane wave plus local-orbital (FP-L(APW + lo)) approach framed within the density functional theory (DFT)” and recognized within WIEN2k computational code. The results of the phase stability show that the GaNxAs1–x alloys are stable for all compositions in the zinc blende phase (B3), except for x = 1, whereas the structure corresponding to the x = 1 composition is found to be more stable in the wurtzite (B4) phase. The physical properties of the more stable phases corresponding to each composition are explored. The pressure-induced phase transition is also investigated, corresponding to each composition. The electronic and optical properties are investigated using the “Tran–Blaha modified Becke–Johnson (mBJ)” potential approach. To explore the thermal properties, the "quasi-harmonic Debye model" approach is employed. Our calculated results of the absorption coefficients and optical band gap show that these alloys could be appropriate candidates for applications in solar cells and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Context: In this work, a comprehensive study concerning the physical properties of ternary alloys system (AlP1−xBix) at different concentrations is presented. The obtained results from our first-principle calculations are compared with previously reported studies in the literature and discussed in detail. Our computed results are found in a nice agreement where available with earlier reported results. Electronic band structures at the above-mentioned concentrations are also determined. Likewise, the impact of the varying temperature and pressure on Debye temperature, heat capacity, and entropy is analyzed as well. Furthermore, elastic constants and related elastic moduli results are also computed. Our results show that alloys are stable and found to be in brittle nature. This is the first quantitative study related to ternary alloys (AlP1−xBix) at mentioned concentrations. We soon expect the experimental confirmation of our predictions. Method: The calculations are performed, at concentrations x=0.0, 0.25, 0.5, 0.75, and 1.0 by using the "full potential (FP) linearized (L) augmented plane wave plus local orbital (APW+lo) method framed within density functional theory (DFT)" as recognized in the "WIEN2k computational code". The "quasi-harmonic Debye model" approach is employed to determine the thermal properties of the title alloys. [ABSTRACT FROM AUTHOR]