We investigate the double perovskite compound Ba2NiUO6 and its electronic, magnetic, elastic, thermodynamic, and thermoelectric characteristics. Specifically our research demonstrates that Ba2NiUO6 crystallizes in a stable cubic structure \( \left( {{\text{Fm}} - \bar{3}{\text{m}},} \right. \) a = 8.292 Å) and functions as a half-semiconductor with a direct band gap of 1.47 eV (spin-up) and an indirect band gap of 1.58 eV (spin-down). In addition the compound exhibits a total magnetic moment of 2 µB, primarily from Ni 3d orbitals, while phonon dispersion analysis confirms the dynamical stability with minimal imaginary frequencies. Moreover the elastic constants indicate that the material is mechanically stable and maintains a well-balanced ductile–brittle characteristic. The thermoelectric investigations further demonstrate optimal performance at low temperatures, achieving ZT = 1 in the spin-down channel. Furthermore, thermodynamic properties, including a high Debye temperature (521 K) and favorable heat capacities, underscore its suitability for practical applications. Hence, Ba2NiUO6 is identified in this work as a multifunctional material that enables new applications in spintronic devices, energy conversion, and sustainable technology.
