Investigation on BCZT piezoelectric ceramics by two-step sintering method

Ion doping and microstructure optimization are effective methods for enhancing the piezoelectric properties of Ba0.88Ca0.12Ti0.88Zr0.12O3 (BCZT) ceramics. To investigate the combined effects of Fe3+ doping and grain size on the piezoelectric properties , we doped 0.1 mol% Fe into BCZT and sintered at various temperatures using two-step sintering method. Our results indicate that Fe3+ doping caused the lattice of BCZT to shrink while increasing sintering temperatures, the sintering process was accelerated, resulting in larger grain sizes. It is believed that relatively large grains usually induce larger domains, facilitating the motion of domain walls, and increasing remnant polarization. However, excessively high sintering temperatures and large grain sizes may cause unfavorable compositional changes and harm densification, leading to a reduction in piezoelectric properties, such as d33 and Tc. In this study, the BCZT ceramic samples that were calcined at 1200°C and sintered at T1 of 1550°C and T2 of 1300°C exhibited the optimal performance, with the highest remnant polarization (Pr) ~14.8 μC/cm2, the largest piezoelectric constant (d33) ~420 pC/N at room temperature, and the highest Curie temperature (Tc) ~115°C. These findings suggest that Fe3+ doping and sintering optimization are effective methods for discovering high-performance BCZT ceramics through microstructure optimization.