Effect Of Composition And Process On The Properties Of PZSN Quaternary Ceramics

In this paper, Pb(Sn_1/3Nb_2/3)O₃-Pb(Zn_1/3Nb_2/3)O₃-PbZrO₃-PbTiO₃ (PZSN) quaternary piezoelectric ceramics were prepared by conventional solid solution method. Meanwhile, the effects of different Zr/Ti ratio and optimizing processing on the microstructure, piezoelectric and mechanical properties of PZSN ceramics were systemic investigated. The X-ray diffraction (XRD) and the scanning electronic microscope (SEM) were applied to analyze phases and microstructure, respectively. The study on the properties of the system doped by Pr₆O₁₁ indicated that the MPB of the tetragonal and rhombohedral phase lay in the vicinity of Zr/Ti=45/43. The properties optimized for high-power applications such as transformers, ultrasonic motors, and electromechanical transducers were obtained with Zr/Ti=45/43 at calcination temperature of 960℃and sintering temperature of 1260℃. The main parameters: dielectric constantε^T₃₃/ε₀=2113, dielectric loss tanδ=0.016, piezoelectric constant d₃₃=420pC/N, coupling coefficient K_p =66.4%, mechanical quality factor Q_m=923, Cure temperature T_c=320℃. The temperature coefficient of resonant frequency obtained a minimum value (Δf_r/f_r25℃=0.25%) at Zr/Ti=45/43. Also, the change of K31,d₃₁,ε₃₃^T/ε₀,tanδat Zr/Ti=45/43 was smoothest.In addition, the effects of different process condition of Pb(Sn_1/3Nb_2/3)O₃-Pb(Zn_1/3Nb_2/3)O₃-PbZrO₃-PbTiO₃( PZSN) quaternary system with adding MnO₂ and Sb₂O₃ on the dielectric and piezoelectric properties of the system were investigated. The result shows that the all samples were of the tetragonal perovskite-type structure. The ratio of c/a decreased because of the adding of MnO₂. But it increased when Sb₂O₃ was doped. Taking to consideration, it can be concluded that 0.5wt% MnO₂ and 0.5wt%Sb₂O₃ doped PZSN ceramics has excellent comprehensive properties for application. The property parameters are listed below:ε^T₃₃/ε₀ =1154,tanδ=0.005,d₃₃=251.5pC/N,K_p=59%,Q_m=1225。...