Ferroelectric fatigue and stabilized piezoelectric properties of BaTiO₃-BaZrO₃ electroceramics with optimized electric poling conditions

Lead-free BaZr_xTi_1-xO₃ (for x = 0, 0.01, 0.02, …., 0.10 in the step of 0.01 mol.%) electroceramics were synthesized by solid-state reaction; to understand the effect of Zr⁴⁺ substitution on the electromechanical, energy storage, and ferroelectric fatigue properties of BaTiO₃ piezoceramics. All ceramics revealed a dense microstructure having an average relative density of > 90%. The BZT1 ceramic exhibits orthorhombic (Amm2 (88%)) + tetragonal (P4mm (12%)) and BZT2 ceramic exhibit Amm2 (86%) + P4mm (14%) phase coexistence and all other ceramics exhibit P4mm crystal symmetries near room temperature. The x = 0.06 (BZT6) revealed the energy storage efficiency and density of ~ 80.18% and 418 mJ/cm³ respectively. The fatigue-free response of all ceramics (10⁶ cycles) is better than PbTiO₃-PbZrO₃ (PZT; 10⁴–10⁵ cycles) ceramics. The parameters such as θ, k_p, and d₃₃ were measured at various electric poling conditions. At an applied voltage of 650 V for 1 h, the pure BaTiO₃ exhibits a θ of 43°, d₃₃ ~ 146 pC/N, and k_p ~ 0.3045, whereas, the maximum d₃₃ value of 148 pC/N was achieved for x = 0.02 (BZT2) even at a lower θ of 28° with k_p ~ 0.3209. However, for x = 0.05 (BZT5) ceramics, the maximum d₃₃ value of 147 pC/N was obtained at the lower θ of 3°, and k_p ~ 0.2249 at 1050 V applied voltage for 1 h. Thus, here we have discussed the fatigue nature as well as the optimization of electric poling conditions for BaTiO₃-BaZrO₃ electro ceramics to invoke better piezoelectric and electromechanical properties along with energy storage ability.