Effect of Li2CO3 Addition on the Sintering Behavior and Physical Properties of PZT-PZN-Pmnn Ceramics

The 0.8Pb(Zr0.48Ti0.52)]O3–0.125Pb(Zn1/3Nb2/3)O3–0.075Pb(Mn1/3Nb2/3)O3 + x wt% Li2CO3 ceramics (PZT-PZN-PMnN), where x = 0  1.0, has been prepared by two-stage calcinations method. The Li2CO3 addition significantly improved the sinterability of the ceramics, resulting in a reduction of sintering temperature from 1150 0C to 930 0C. The effect of the Li2CO3 addition on the sintering behavior and physical properties of ceramic samples have been investigated. Experimental results showed that all samples have pure perovskite phase with tetragonal structure, the c/a ratio increases with increasing of Li2CO3 content. At x = 0.7, electrical properties of ceramics are best: the density () of 7.86 g/cm3, the electromechanical coupling factor, kp = 0.64 and kt = 0.51, the dielectric constant, ε = 1320, the dielectric loss (tan) of 0.005, the mechanical quality factor (Qm) of 1150, the piezoelectric constant (d31) of 145 pC/N, and the remanent polarization (Pr) of 30.5 C/cm2, which makes it as a promising material for high power piezoelectric devices.