Effects of CuO addition on the structure and electrical properties of low temperature sintered Ba(Zr,Ti)O3 lead-free piezoelectric ceramics

CuO-doped Ba(Zr0.05Ti0.95)O3 (BZT) ceramics were prepared using conventional solid state reaction method, and their structure and electrical properties were investigated. It was found that a small amount of CuO could lower the sintering temperature significantly and make their microstructure more densified than pure BZT. The ceramics with 1.2 mol% CuO, sintered at 1250 °C, showed excellent piezoelectric properties with d33~320 pC/N and kp=44%. The sintering temperature was decreased by 150 °C than that for pure BZT ceramics while showing comparable piezoelectric properties. Moreover, the influence of sintering temperature on the optimally 1.2 mol% CuO-doped BZT ceramics was studied. With the temperature change, different patterns of crystal growth were observed in the doped BZT ceramics. When the sintering temperature increased from 1200 °C to 1350 °C, the patterns of normal–abnormal–normal grain growth were changed accordingly.