Effects of poling field on the piezoelectric and dielectric properties of Nb additive PZT-based ceramics and their applications on SAW devices

The piezoelectric lead zirconate titanate (PZT)-based ceramics with a composition of Pb_1-0.5x(Zr_0.52Ti_0.48) _1-xNb_xO₃; x=0.02-0.06 were prepared by conventional mixed-oxide method, using sintering temperature at 1250 °C and poling field at 0-50 kV/cm. Microstructural and compositional analyses of the PZT-based ceramics have been carried out using XRD and SEM. The dielectric constant measured at 1 kHz is about 1500 and the loss factor is small than 0.02. The maximum planar electromechanical coupling coefficient, k_p, is 0.591 as x=0.055 and E_p=30 kV/cm. It showed that the Nb additives were helpful in improving both of the dielectric and piezoelectric properties. Surface acoustic wave (SAW) device, which the PZT-ceramic was used for substrate, was fabricated.