A deep dive into structural, electronic, optical, and mechanical properties of ATiO₃ (A = Ba, Th): DFT insights

Abstract

Abstract Different physical characteristics (structural, optical, electronic, and mechanical) of ThTiO 3 were explored using DFT and compared to BaTiO 3 . ThTiO 3 has been determined to be mechanically and thermodynamically stable based on the simulation results, which were validated using the Born stability criteria and formation energy. Furthermore, a significant modification in the traits of ThTiO 3 has been revealed compared to BaTiO 3 . For example, after the complete substitution of Ba by Th, in the case of GGA-PBE, the band gap increases from 1.82 eV to 3.37 eV, while in the case of HSE-06, it increases from 3.254 eV to 4.21 eV, also converting from indirect to direct bandgap. Not only that, but ThTiO 3 has become an n-type degenerate semiconductor from a conventional semiconductor, which assures potential applications in tunnel diodes, high-frequency transistors, photocatalysts, etc. ThTiO 3 is an appropriate material for capacitors, optoelectronic, and high k nanoelectronics devices based on the high dielectric constant value, which is higher than BaTiO 3 . Moreover, with Th substitution, BaTiO 3 transitioned from brittle to ductile, which ensures its suitability for industrial machining processes. Furthermore, this substitution also improved the material’s anisotropic behavior, as the Zener Anisotropy value for ThTiO 3 is also higher than BaTiO 3 . We believe this investigation will open another door in the field of materials for microelectronics and optoelectronics enthusiasts.