Pb2CoMoO6 as a promising energy material: a first-principles perspective

This study presents a detailed first-principles investigation of the structural, elastic, electronic, optical, and thermoelectric properties of the double perovskite Pb2CoMoO6 compound. The calculations were carried out the full-potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT). We evaluated the energetic stability, the Goldschmidt tolerance factor (tG​), octahedral factor (µ), and modified tolerance factor (τ), formation energy (ΔHf), cohesive energy (Ecoh), phonon dispersion and mechanical characteristics. The findings confirm that Pb2CoMoO6 crystallizes in a perfectly cubic structure belonging to the Fm-3 m space group. Mechanical analysis indicates high elasticity and strength as evidenced by high mass and Young’s moduli, which indicative the stability of the material. The electronic structure calculations reveal half-metallic ferromagnetic (HMF) behavior, with a spin-up band gap of 1.558 eV along the L-Γ direction under the GGA + U approach. Additionally, the compound exhibits an integer magnetic moment of 3.0 µB per formula unit. Moreover, Pb2CoMoO6 exhibits strong optical absorption in the ultraviolet (UV) spectrum and displays promising thermoelectric behavior, with favorable Seebeck coefficients and a high figure of merit (ZTmax≈1) at room temperature, suggesting potential for applications in spintronic and thermoelectric devices.