Study On The Properties Of PMS-PZN-PZT Quaternary Piezoelectric Ceramics

Pb(Mn_1/3Sb_2/3)O₃-Pb(Zn_1/3Nb_2/3)O₃-PbZrO₃-PbTiO₃ (PMS-PZN-PZT) quaternary piezoelectric ceramics were prepared by conventional solid solution method. The samples were gained by adding MnO₂, Ni₂O₃ in order to enhance the properties. The X-ray diffraction (XRD) and the scanning electronic microscope (SEM) were applied to analyze phases and microstructure, respectively. The effects of the composition and the sintering temperature on the dielectric and piezoelectric properties and temperature stability of the system were also discussed. The study on the properties of the system indicated that the MPB of the tetragonal and rhombohedral phase lay in a broad composition region. The optimum properties were obtained with Zr/Ti=50/50 at calcination temperature of 850℃and sintering temperature of 1245℃. The main parameters:ε₃₃T/ε₀=1243, tanδ=0.004, d₃₃=296pC/N, K_p =0.532, Q_m=1605, T_c=297℃. The temperature coefficient of resonant frequency shifted from plus (+) into minus (-) value with increasing Zr/Ti ratio and obtained a minimum value at Zr/Ti=50/50, which reflected the transition from tetragonal phase to rhombohedral phase.In addition, PMS-PZN-PZT quaternary system doped by Mn, Ni close to the the morphotropic phase boundary (MPB) were investigated systematically as a function of Mn doping and sintering temperature. Doping of Mn shifted compositions away from the MPB toward the rhombohedral phase, greatly reduing the Curie temperature and broadening the dielectric constant maximum. When calcination temperature is 850℃and sintering temperature is 1220℃, the optimum properties ofε₃₃T/ε₀ (1244), tanδ(0.004), d₃₃ (277pC/N), K_p(0.62), Q_m(2415), T_c(280℃) were obtained with Mn=0.1wt% and Zr/Ti=50/50.