First-principles investigation of structural, electronic, mechanical, and thermal properties of ternary silver-based alloys (XAgSi; X = Cu, Ti, Sc)

Abstract In this work, the structural, electrical, mechanical, and thermoelectric properties of ternary silver-based alloys XAgSi (X = Cu, Ti, Sc) are thoroughly investigated from fundamental principles utilizing density functional theory (DFT) applied to the WIEN2k code. A variety of exchange–correlation functionals, such as the modified Becke–Johnson potential, PBE-GGA, and HSE06 hybrid functional, were used to precisely predict the band gaps and electronic structures of the samples. According to Born stability criteria, cubic crystal formations with outstanding mechanical stability are revealed by structural investigation. According to electronic structure simulations, CuAgSi behaves metallically, ScAgSi has a semiconducting property with an indirect band gap of 0.95 eV (HSE06), and TiAgSi exhibits ferromagnetic metallic behavior from Ti-3d and Si-3p hybridization with noticeable spin polarization. Optical properties analysis revealed unique dielectric responses and high absorption of visible light appropriate for optoelectronic applications. The thermoelectric characterisation of the ScAgSi shows a viable contender for low-temperature thermoelectric applications with an outstanding figure of merit (zT) of 4.9 at 100 K and a peak Seebeck coefficient of 211 μV K −1 at 600 K. Mechanical property investigation of the ScAgSi ternary compound exhibits the maximum stiffness with a Young’s modulus of 68.256 GPa and a Debye temperature of 281.433 K, while Pugh’s ratios below 0.4 show ductile behavior. The significant anisotropy in TiAgSi and ScAgSi contrasts with the near-isotropic mechanical behavior of CuAgSi, underscoring the crucial impact of transition metal selection. These results show that computational materials design is effective in predicting multifunctional properties and provide a thorough foundation for the structure–property relationship for silver-based ternary alloys.