LAUSR

For many BNT-based ceramics, an attempt to increase the piezoelectric properties usually results in a decrease in depolarization temperature (Td). This trend limits the applications of the materials. Many previous experiments have used different methods to enhance the piezoelectric properties and improve the Td characteristic. In this study, we demonstrated a simple technique (thermal annealing) to enhance the piezoelectric properties with a very slight decrease in Td by ∼2 °C for a modified BNKT ceramic (BNKT doped with ZnO). Other phase transition characteristic temperatures of the studied ceramics were also slightly changed. The optimum dielectric (εr = 651, tan δ = 0.0503, TF–R = 167.38 °C, Tm = 305.41 °C, εmax = 5551, TB = 367.15 °C, Td = 155.98 °C, and γ = 1.43), ferroelectric (Pmax = 41.28 μC cm−2, Pr = 35.85 μC cm−2, Ec = 42.60 kV cm−1 and Rsq = 1.42), piezoelectric (d33 = 198 pC N−1, kp = 0.598, and g33 = 34.35 × 10−3 Vm N−1), and energy harvesting (FoM = 6.80 pm2 N−1) were obtained for the 8 h annealed ceramic. Furthermore, higher energy harvesting properties (which were 32% higher than that of the unannealed ceramic) were obtained after employing this technique.