Defect engineering of BCZT-based piezoelectric ceramics with high piezoelectric properties

The intrinsic conduction mechanism and optimal sintering atmosphere of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ (BCZT) ceramics were regulated by Mn-doping element in this work. By Hall and impedance analysis, the undoped BCZT ceramics exhibit a typical n-type conduction mechanism, and the electron concentration decreases with the increasing oxygen partial pressure. Therefore, the undoped ceramics exhibit best electrical properties (piezoelectrical constant d₃₃ = 585 pC·N^-1, electro-mechanical coupling factor k_p = 56%) in O₂. A handful of Mn-doping element would transfer the conduction mechanism from n-type into p-type. And the hole concentration reduces with the decreasing oxygen partial pressure for Mn-doped BCZT ceramics. Therefore, the Mn-doped ceramics sintered in N₂ have the highest insulation resistance and best piezoelectric properties (d₃₃ = 505 pC·N^-1, k_p = 50%). The experimental results demonstrate that the Mn-doping element can effectively adjust the intrinsic conduction mechanism and then predict the optimal atmosphere.