Engineering Room-Temperature Ferroelectricity in NaNbO3 via (Ba0.7Ca0.3)TiO3 substitution: A Combined Structural and Ferroelectric Investigation at Elevated Temperatures

Sodium niobate, a promising material for energy storage, has been transformed into a room-temperature ferroelectric phase through a well known crystal engineering technique. This involved strategically substituting atoms within the crystal structure (A and B sites) to induce chemical pressure. The resulting material exhibits enhanced polarization strength at elevated temperatures, with the underlying mechanism linked to atomic displacements and octahedral rotation or distortions within the crystal lattice. This connection between structure and properties is further supported by the good agreement between computed polarization values and experimental data. Interestingly, the research also unveils the material's temperature-dependent phase transitions, transitioning from a ferroelectric phase at room temperature (Pmc2₁) to a high-symmetry paraelectric phase ($\mathrm{P}m\bar{3}m$$\mathrm{P}m\bar{3}m$) as temperatures increase. This work opens exciting possibilities for developing novel energy storage devices utilizing this engineered ferroelectric material.