Unlocking the secrets of pressure-driven physical properties of NaNbO3 perovskite-oxide: A computational insight

The current investigation presents the various pressure-induced properties such as structural, elastic, mechanical, optical, and electronic features of NaNbO3 across a pressure range of 0.0–100 GPa. Utilizing the CASTEP tool alongside GGA-PBE based on DFT, comprehensive calculations are conducted. The material displays an indirect energy bandgap, with its magnitude increasing from 1.633 to 2.223 eV under rising pressure. Analysis reveals a covalent character in O–Nb bonds, while O–O and Na–O interactions exhibit an ionic nature. As pressure rises, both lattice parameters and volume exhibit a tendency to decrease. Interestingly, the material exhibits anisotropic behaviour and maintains mechanical stability, transitioning from brittleness at 0.0 GPa to ductility between 10 and 100 GPa. Additionally, it demonstrates superhard characteristics at 0.0–20 GPa and progresses to an ultrahard state from 30 to 100 GPa. Optical properties display a trend of sharpening peaks with a slight shift towards higher energy in the curves. Notably, the material's indirect bandgap renders it suitable for prolonged photocatalysis applications.