Excellent comprehensive piezoelectric performances of SiC-doped BCTZ-based lead-free piezoelectric ceramics

With the increasing awareness of environmental protection, the electrical performances and sintering process of lead-free piezoelectric ceramics are continuously optimized to replace the lead-based materials. Exploring the appropriate doping strategy is believed to achieve the concurrent improvement for the lead-free piezoelectric ceramics. In this work, SiC was selected to optimize the phase structure, defect configuration, morphology of (Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ lead-free piezoelectric ceramics. On the one hand, the SiC could promote the sintering process and grain growth due to its excellent thermal conductivity, resulting in the compactness and outstanding insulation of the doped ceramics. On the other hand, the incorporation of Si⁴⁺ in the B-site of ABO₃ lattice not only deforms the crystal structure and enhances the lattice distortion, but also reduces the oxygen vacancy concentration and improves the charge carrier activation energy. As a result, the excellent comprehensive piezoelectric responses of d₃₃ = 638 pC/N, d₃₃^* = 1048 pm/V, k_p = 58.21%, and T_c of ~ 95 ^oC were achieved in the optimized composition. Our work demonstrated that the SiC doped BCTZ-based ceramics are potential candidate to replace lead-based piezoceramics.