Half-Metallic Ferromagnetism and Enhanced Thermoelectric Response in Cubic A₂NaVBr₆ Double Perovskites: A First-Principles Study

The advancement of materials science increasingly focuses on predicting novel and functional materials, often driven by rapid screening enabled through high-throughput density functional theory calculations. The improved illustration for the advancement and development of numerous materials is typically predictable on the ab initio method for the clarification of the numerous materials. The first-principles method is implemented to examine the electronic band profile, thermoelectric characteristics, and elastic features of the vanadium-based perovskite A₂NaVBr₆ (A = K, Rb, Cs). The modified Becke–Jhonson potentials (mBJ) and the GGA are taken as simulation approximations to evaluate the numerous potentials. The pressure and temperature dependence on thermodynamic factors, especially volume, bulk moduli, heat capacity, and Grüneisen parameter which have been taken in pressure (0–5 GPa) and as well as temperature range (0–500 K), are also presented via a quasi-harmonic Debye model, and this conveys a thought-provoking future opportunity for specific uses. The figure-of-merit acquires its maximum value of 0.36 (K), 0.25 (Rb) and 0.38 (Cs) at elevated temperatures (1000 K), based on the valuation of the thermoelectric transport properties. Appropriate thermoelectric properties exhibiting a half-metallic performance and brittle quality designate the likelihood of integrating materials to lend their path for spintronic devices and for thermoelectric materials.