Exploring Novel Ba2MBiO6 (M = Sm, Tb) Oxide Double Perovskites Employing DFT

In the present work, we investigate the structural, elastic, optical, and electronic properties of Ba2MBiO6 (M = Sm, Tb) oxide double perovskites, using Density Functional Theory within the Wien2k The generalized gradient approximation GGA for structural and elastic properties while the Tran-Blaha modified Becke-Johnson Tb-mBJ is employed for both optical and electrical properties. The Birch-Murnaghan equations of state and tolerance factors are used to verify the structural stability of both compounds. It is determined that both systems are elastically stable and have anisotropic ductile and ionic bonding behavior. The Ba2SmBiO6 is a non-central force crystal nu = 0.51 as with Ba2TbBiO6 a central force crystal nu = 0.29. Finally, as a potential candidate for spintronic applications, Ba2SmBiO6 shows half-metallic behavior exhibiting spin-dependent band gaps. Ba2TbBiO6 behaves as a direct band gap semiconductor with a 1.79 eV band gap. Both compounds have optical properties in the UV-visible region, indicating potential for optoelectronic applications.