Theoretical investigation of Sr2TmWO6 (Tm=Cr, Fe, and Co): Analyzing structural, mechanical, optoelectronic and thermoelectric properties for enhanced spintronic and thermoelectric applications

This study explores the structural, elastic, dynamic, electronic, magnetic, thermal, and optical properties of Sr2TmWO6 double perovskites (Tm = Cr, Fe, Co) using Density Functional Theory (DFT) and the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method. We applied the Generalized Gradient Approximation (GGA) and the modified Becke-Johnson potential (TB-mBJ) to enhance band gap predictions, in addition to the GGA + U method to address strong electron correlations. The compounds crystallize in a cubic structure (space group Fm3‾m) with negative formation energies, indicating their stability. Our results demonstrate the presence of thermodynamically stable cubic phases of Sr2TmWO6, all exhibiting significant mechanical and dynamical stability, as confirmed by our evaluations of elastic constants and phonon spectra. The magnetic moments of 2, 3, and 4 μB for Sr2CrWO6, Sr2CoWO6, and Sr2FeWO6 respectively, confirm their half-metallic characteristics, making them strong candidates for spintronic applications. Furthermore, these compounds show promising optical properties for UV device applications. Their thermoelectric performance is particularly impressive, achieving ZT values close to unity over a wide temperature range, which emphasizes their potential in thermoelectric applications. This comprehensive analysis deepens our understanding of Sr2TmWO6 compounds and highlights their importance in advanced materials science, especially in spintronics and thermoelectrics. •This study presents a comprehensive theoretical investigation of the structural, electronic, magnetic, thermal, optical, and elastic properties of the Sr2TMWO6 (TM = Cr, Fe, and Co) double perovskite compounds.•Various approximations, including the Generalized Gradient Approximation (GGA), GGA + U methods and the modified Becke-Johnson (TB-mBJ) approach was employed.•In this work was examined band gaps, magnetic moments, and the thermoelectric figure of merit (ZT) as functions of the Hubbard U parameter.•As a results; this compounds has a half-metallic nature, making them promising candidates for various Spintronic and thermoelectric applications.