Electric-field-induced antiferroelectric to ferroelectric phase transition in hot-pressed PbZrO₃

Double polarization hysteresis loops associated with field-induced antiferroelectric-ferroelectric (AFE-FE) phase transitions, which underpin many antiferroelectric functionalities, are rarely observed in PbZrO₃ polycrystals at ambient conditions because the required critical field often approaches the dielectric breakdown strength. Here, dense PbZrO₃ ceramics fabricated by hot pressing reach 97.8% relative density and exhibit an orthorhombic Pbam average structure, as confirmed by high-energy X-ray diffraction. A sharp paraelectric-antiferroelectric anomaly is observed at 235 °C, with a peak permittivity of 5387 at 10 kHz and negligible frequency dispersion. Room-temperature polarization measurements demonstrate a field-induced AFE-FE transition can be triggered at 27 kV/mm, yielding well-defined double hysteresis loops with forward and backward critical fields of 26.5 kV/mm and 19.1 kV/mm, respectively. The ceramics deliver a recoverable energy density of 3.6 J/cm³ with an efficiency of 73.5%, accompanied by a large field-induced strain of 0.49%. Large-signal dielectric measurement reveals a non-monotonic field dependence of permittivity, featuring a pronounced enhancement as the forward transition is approached. Atomistic-resolution electron microscopy and polarization mapping directly resolve the commensurately modulated antipolar “↑↑↓↓” order and quantify an average Pb displacement of ~24 pm with dipoles aligned along <110> directions. These results establish a room-temperature experimental benchmark for pristine bulk PbZrO₃, linking atomistic-scale antipolar order to macroscopic transition and providing a quantitative baseline for evaluating phase competition and transition pathways in antiferroelectric perovskites.