Synergistic enhancement of electrical characteristics in Sr2+ and Zr4+ Co-doped BaTiO3 ceramics through multiphase coexistence regulation at room temperature

BaTiO 3 (BT)-based ceramics have recently become one of the most promising lead-free piezoelectric ceramics . However, its overall performance still falls short of meeting the demands for multifunctional applications. Although phase boundary regulation can enhance the piezoelectric properties , BT ceramics have very separate phase transition temperatures for different phases. This leads to the difficulty of achieving multiphase coexistence at room temperature (RT). In this work, based on doping 0.08 mol Zr 4+ , the lead-free Ba 1- x Sr x Ti 0.92 Zr 0.08 O 3 [ x  = 0, 0.04, 0.08, 0.12, 0.16, 0.20 (mol), B 1- x S x TZ] piezoelectric ceramics were prepared using the solid-state reaction method, and the effect of the Sr 2+ doping level on the multiphase structural evolution and piezoelectric properties was systematically investigated. The results demonstrated that with the increase in the Sr 2+ doping content, multiphase coexistence within the B 1- x S x TZ ceramics was successfully achieved at RT. Moreover, it showed significant synergistic improvements in piezoelectric, dielectric , and electric-field-induced strain properties. At the doping level of about x  = 0.16 mol, the key performance metrics of the piezoelectric ceramics were optimal. The d 33 at room temperature reached ∼447 pC/N, k p ∼0.49, and ε r ∼4649. Under an applied electric field of 10 kV/cm, S pos was ∼0.092 %, and d 33 ∗ was ∼895 p.m./V. Therefore, this study provides new insights into the progress of advanced lead-free piezoelectric materials for multifunctional applications.