Effect of CuO on the microstructure and electrical properties of Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ piezoceramics

In this study, the effect of CuO content on the microstructure and electrical properties of Ba_0.85Ca_0.15Ti_0.90Zr_0.10O₃ (BCZT) ceramics was systematically studied. The addition of CuO effectively results in an increase of grain sizes in BCZT ceramics. BCZT ceramics endure a lattice distortion due to the Cu²⁺ part substitution for the Ti⁴⁺ site, and a low-sintering temperature of BCTZ ceramics is induced by the addition of CuO. With increasing CuO content, the dielectric constant and the dielectric loss of BCTZ ceramics decrease, together with the decrease of the remanent polarization and the coercive field. Effects of sintering temperature and dwell time on the microstructure and electrical properties of BCZT ceramics with x = 0.5 mol% CuO were also studied, and an optimum sintering condition helps to further improve its electrical properties. BCZT ceramics with x = 0.5 mol% CuO possess optimum electrical properties: d ₃₃ ~ 403 pC/N and k _p ~ 44.6% when sintered at a low temperature of 1400 °C for 6 h. As a result, BCZT ceramics with a sintering aid of CuO are a promising candidate for the transducer and transformer applications.