Fabrication and electrical characteristics of piezoelectric PMN–PZN–PZT ceramic transformers

For the fabrication as piezoelectric transformers, the density, microstructure, dielectric and piezoelectric properties of Pb(Mg1/3Nb2/3)O3–Pb(Zn1/3Nb2/3)O3–Pb(Zr0.52Ti0.48)O3 (PMN–PZN–PZT) ceramics as a function of calcining temperature and sintering temperature were investigated. In addition, the piezoelectric transformers with the composition of PMN–PZN–PZT were fabricated and the characteristics with various resistance loads were measured. The results indicated that the optimized properties of ceramics were obtained at calcining temperature of 800 °C and sintering temperature of 1020 °C, which were listed as follows: d33 = 249 pC/N, Kp = 0.57, Qm = 1954, ɛr = 1122 and tan δ = 0.0059. Meanwhile, piezoelectric transformers sintered at 1020 °C show the favorable characteristics with a higher step-up ratio of 145 and a lower temperature rise of 5 °C at 250 kΩ.