Aliovalent substitution of Pb with (Li _1/2 Bi _1/2 ) in PbZrO ₃ model system

Abstract Li + and Bi 3+ (at 1:1 ratio) substitution of Pb 2+ in the model compound PbZrO 3 is investigated. It is found that [Pb 1− x (Li 1/2 Bi 1/2 ) x ]ZrO 3 ceramics remain phase pure of orthorhombic perovskite at x = 0.05, are almost phase pure at x = 0.10 and 0.15, and contain minor amounts of impurity phases at x = 0.20. The substitution allows the ceramics to be sintered to a high density at reduced temperatures, and at the same time, significantly enhances the dielectric breakdown strength. At 160°C when reversible antiferroelectric (AFE)–ferroelectric (FE) phase transitions are observed in all compositions, the chemical substitution is shown to reduce the electric hysteresis, increase the energy storage density, and improve the energy efficiency. The results will help design future high‐performance ceramics for energy storage capacitors. It is further observed that the (Li 1/2 Bi 1/2 ) substitution of Pb in PbZrO 3 weakly impacts the dielectric behavior of the ceramics: The temperature at dielectric maximum, T m , varies within a narrow range of 232.4–237.6°C; the relaxation parameter in the paraelectric phase, γ , stays close to unity and barely changes; and the diffuseness parameter of the phase transition at T m , d , remains low. Defect dipoles of preferably along 〈1 1 0〉 directions are proposed to explain the un‐disrupted long‐range AFE order in the [Pb 1− x (Li 1/2 Bi 1/2 ) x ]ZrO 3 ceramics.