Barium titanate-based perovskites for multifunctional applications: comprehensive computational and experimental...

Barium titanate is a renowned ferroelectric material with a perovskite structure. This comprehensive study explores various properties of these perovskites for widespread applications. Density functional theory calculations were performed to predict the influence of Mg on different parameters. Uniform thin films of these materials were grown in a phase-pure form for experimental investigations. Crystallographic analysis confirmed a cubic phase perovskite structure in these compositions. The morphological analysis of the pure composition demonstrated aggregated, randomly scattered grains, which were strategically altered upon Mg doping. Distinct orbital contributions of the Ba-p, O-p, Ti-d, and Mg-s states were depicted in the Mg-doped compositions. Introduction of Mg effectively tuned the thermoelectric response of the BaTiO₃ matrix, modifying the figure of merit and Seebeck coefficient. The composition doped with the highest maximum Mg content presented a refractive index and epsilon value of ≈3.35 and ≈8.5, respectively, in the experimental evaluation of optical parameters. The optical bandgap of the BaTiO₃ lattice markedly reduced from 2.3 eV to 1.71 eV after Mg doping; these enhanced parameters make it a promising material for future optoelectronics.