Effects of BiAlO₃ substitution on the structures and properties of antiferroelectric PbZrO₃

Antiferroelectrics (AFEs) like PbZrO₃ (PZ) are promising materials for energy storage, but they face a major issue: their critical field (E_cr) exceeds the dielectric breakdown strength (DBS), preventing dipole switching and limiting its practical applications. In this work, the AFE order of PbZrO₃ is softened by stoichiometric substitution of ferroelectric BiAlO₃ (BA) to form the (1 − x)PZ-xBA solid solution which exhibits an increased DBS, making the AFE to ferroelectric (FE) switching possible. It is found that the structures and properties of the high temperature intermediate phase existing between T_C1 and T_C2 are different in the composition ranges of 0 ≤ x ≤ 0.01 and 0.01 ≤ x ≤ 0.05. The Rietveld refinements of the intermediate phase for x = 0.03 at various temperatures reveal the coexistence of the rhombohedral R3c symmetry and the orthorhombic Pbam space group. For x = 0.02, a ferrielectric-like hysteresis loop is observed under high electric fields, while, for x = 0.03, the increased DBS allows the application of high electric fields, enabling the AFE-to-FE switching at room temperature. Double hysteresis loops are displayed between T_C1 and T_C2 for x = 0.01-0.05 at high temperatures, indicating that the BA substitution transforms the intermediate phase from ferroelectric to antiferroelectric in the (1 − x)PZ-xBA solid solution. An energy storage density (W_rec) of 0.4 J cm⁻³ is achieved for x = 0.04 at 220 °C under a relatively low electric field of 40 kV cm⁻¹, which is double that of pure PZ, making it suitable for dielectric capacitors for energy storage applications at high temperatures.