Is a Fully Dense (>98%), Phase‐Pure Tetragonal BaTiO ₃ Ceramic via Conventional Sintering Routes Enough to Ensure a Typical Ferroelectric Behavior?

The current work emphasizes the importance of a saturated polarization–electric (P–E) field hysteresis loop response for ensuring ferroelectricity in a system. Even the “so called” strong evidences of a phase‐pure tetragonal, high density (>98%), low loss (tan δ  < 0.03) BaTiO ₃ ceramics with sharp dielectric anomaly versus temperature plots could not show saturated P–E loops. Starting from an industrial grade commercial BaTiO ₃ precursor, a single‐step conventional sintering profile yielded worst ferroelectric response, while the two‐step sintered ceramics assured ferroelectricity. This is in sharp contrast to many oxide ceramics where a single‐step sintering profile is generally considered to be good enough for the chosen property/application. Along with different microstructural development, the formation of oxygen vacancy‐related defect complexes (for the single‐step sintered ceramic) was assigned to be the possible reason for promoting extrinsic dielectric contributions which eventually prevented the domain wall mobilities in BaTiO ₃ ceramic.