Résumé: The full potential linearized augmented plane wave (FP-LAPW) technique was performed to give valuable insights into the elasto-mechanical, electronic structure, and magneto-optical characteristics of the cubic double perovskite oxide Sr2AlMoO6. The prediction of structural properties demonstrates the compound’s enduring ferromagnetic stability. The generalized gradient approximation (GGA) and the GGA + U approach were performed to calculate the spin-polarized electronic band structure and density of states, which revealed that the compound exhibits a half-metallic characteristic, whereas most spin channels exhibit metallic behavior. In contrast, a minority of spin channels display semiconducting properties. The calculated significant values of the bulk and Young modulus also categorize the material as robust and more rigid The computed values for B/G and Cauchy pressure (C12-C44) collectively indicate the compound’s ductile characteristics. The calculations of different optical spectra affirm that this compound is highly suitable for various device applications across a wide range of the electromagnetic spectrum.

Résumé: Making products that are affordable, environmentally friendly, and energy- efficient is the main objective of modern production. The objective of this research is to discover compounds that meet these parameters. The full-potential, linearized augmented plane wave program (FP LAPW) offered by Wien2K was used to examine the structural, optical, electrical, and transport aspects of SrCaGe and SrCaSn Half-Heusler (HHs) compounds. Generalized gradient approx- imation (GGA) was considered for the structural optimization and computation of elastic properties signifies inherent ductility and mechanical stability of the exam- ined SrCaGe and SrCaSn compounds. Additionally, both materials were found to possess a direct bandgap and exhibit semiconducting behavior. The bandgap mag- nitudes obtained utilizing the modified Becke-Johnson (mBJ) approximation are 0.78 and 0.52 eV for SrCaGe and SrCaSn, respectively. According to their optical characteristics, SrCaGe and SrCaSn show potential for application in optoelec- tronic components. Furthermore, the transport properties are evaluated by BoltzTrap program, revealing that both SrCaGe and SrCaSn exhibit figures of merit (ZT) values nearly equal to one at room temperature. This suggests their potential use in creating thermoelectric devices with highly efficient performance. The simulation study demonstrates the promising attributes of SrCaGe and SrCaSn HHs materials, positioning them as viable candidates for various applica- tions, aligned with the goals of sustainable and efficient manufacturing.

Résumé: Ab initio calculations based on density functional theory using the full-potential linearized augmented plane wave method have been carried out to find the structural stability of different crystallographic phases, the pressure-induced phase transition and the electronic properties of the magnesium chalcogenides MgS, MgSe and MgTe. The zinc blende (B3), wurtzite (B4), rock salt (B1), CsCl (B2), NiAs (B8), β-BeO, 5-5 and TiP crystal structures are considered and the exchange and correlation potential is treated by the generalized-gradient approximation using the Perdew–Burke–Ernzerhof parameterization. Moreover, the modified Becke-Johnson (mBJ) scheme is also applied to optimize the corresponding potential for the band structure calculations. Results show that the wurtzite phase is the stable structure in the ground state adopted by MgSe and MgTe compounds while MgS adopts the rock-salt one. Moreover, the band structure calculations reveal a metallic behavior in the CsCl structure for all the compounds, whereas for the other structures, a semiconducting behavior is observed.