Effect of sintering conditions on characteristics of PbTiO3–PbZrO3–Pb(Mg1/3Nb2/3)O3–Pb(Zn1/3Nb2/3)O3

In this work, the piezoelectric ceramic system of the Pb[(Zr1−yTiy)0.74(Mg1/3Nb2/3)0.20(Zn1/3Nb2/3)0.06]O3, 0.47≤y≤0.57, with composition close to the morphotropic phase boundary (MPB) is studied. From the results of X-ray diffraction and piezoelectric measurement, ceramics near y=0.51 are found at the MPB between the tetragonal and pseudocubic perovskite. The effects of sintering time and packing powders on the properties of Pb[(Zr0.49Ti0.51)0.74(Mg1/3Nb2/3)0.20(Zn1/3Nb2/3)0.06]O3 (PZT–PMN–PZN) ceramic are discussed. Dielectric and piezoelectric properties have maximum values at the sintering temperature of 1250 °C for 3 h. Longer sintering time causes excessive PbO loss and a resultant variation in composition, which leads to an inhomogeneous microstructure and the emergence of a pyrochlore phase. The pyrochlore phase is detrimental to the dielectric and piezoelectric properties. The PZT–PMN–PZN piezoceramics system, which has excellent dielectric and piezoelectric properties, uses uncalcined powder of the main component as the packing powder to provide a positive vapor pressure.