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Double perovskites are promising for solar cells, thermoelectric generators, and renewable energy due to their stability, eco-friendly nature, lack of lead, and high performance. This study uses first-principles calculations to examine the structural, dynamical, elastic, and optoelectronic properties of Ba₂PrXO₆ (X = Ir, Pt) with WIEN2k code. The ferromagnetic (FM) state is more stable than the non-magnetic (NM) state for both compounds, with Ba₂PrIrO₆ having formation energy of − 1.354 being slightly more stable than Ba₂PrPtO₆ with formation energy of − 1.258. Both compounds are dynamically and mechanically stable with C11 values of 305 for Ba2PrIrO6 and 322 for Ba2PrPtO6, ductile, anisotropic, resistant to plastic deformation, and exhibit ionic bonding and central force crystal characteristics. Electronic band structure calculations reveal that Ba₂PrIrO₆ behaves as a metal in both spin channels with PBE but shows direct bandgap semiconductor behavior for the spin-down channel (1.51 eV) with PBE-mBJ. Ba₂PrPtO₆ is identified as an indirect bandgap semiconductor by both methods. Both compounds show significant electronic transitions in the UV spectrum, indicating potential for UV absorption applications. [ABSTRACT FROM AUTHOR]

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 ν = 0.51 as with Ba2TbBiO6 a central force crystal ν = 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. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical investigation utilizing the full-potential linearized augmented planewave method (FP-LAPW) within density functional theory (DFT) framework, implemented in the Wien2k program. Analysis reveals that Sr2DySbO6 (t = 0.991) and Sr2LaSbO6 (t = 1.01) exhibit theoretical tolerance factors suggesting their crystallization in a face-centered cubic form (FCC) with space group (Fm3m; No. 225). Notably, Sr2DySbO6 demonstrates a slightly higher stability (χ_ value of 2.1207) compared to Sr2LaSbO6 (χ_ value of 1.9902). Both compounds also show negative formation energies, suggesting that they are feasible for experimental synthesis and structurally stable. Stability is further confirmed by structural optimization by atomic relaxation and total energy reduction against unit cell volume. Both compounds exhibit ductility, anisotropy, ionic bonding nature, elastic stability, resistance to plastic deformation, and central force crystal properties. Sr2DySbO6 electronic characteristics reveals that it is metallic, whereas Sr2LaSbO6 is insulating. Energy-wise, optical properties are assessed between 0 and 15 eV. Both the compounds have demonstrated noteworthy UV responses are making use of the unique characteristics and high energy of UV light for a range of creative uses. Overall, these findings advocate for experimental exploration of these compounds, hinting at potential applications. [ABSTRACT FROM AUTHOR]