(Ba, Ca)(Ti, Zr)O3-BiFeO3 lead-free piezoelectric ceramics

Effects of BiFeO3 (BFO) content on the microstructure and electrical properties of Ba0.85Ca0.15Ti0.90Zr0.10O3 (BCTZ) ceramics prepared by normal sintering in air were investigated. A stable solid solution is formed between BCTZ and BFO. The grain size gradually becomes smaller, and the ceramics become denser with increasing the BFO content. The Curie temperature, dielectric constant, and dielectric loss of BCTZ ceramics decrease simultaneously with the introduction of BFO. Moreover, the remanent polarization reaches a maximum at x = 0.2 mol%, and the coercive field continuously increases with increasing the BFO content due to the introduction of BFO with a higher coercive field. Improved piezoelectric properties (d33 ∼ 405 pC/N and kp ∼ 0.44) are demonstrated for the BCTZ ceramic with x = 0.2 mol%.