High Piezoelectric Property and Low Dielectric Constant PZN-PZT Ceramics

摘要

The influences of the substitution of (Zn_(1/3)Nb_(2/3)) group for Ti as well as addition of Fe_2O_3 and K_2CO_3 on d_(33), k_p, ε_r, and tgδ of the Pb[Zr_(0.46)Ti_(0.54-x)(Zn_(1/3)Nb_(2/3))_x]O_3 + y mol%Fe_2O_3+z mol%K_2CO_3 (PZN-PZT) (0 ≤ x ≤ 0.20, 0 ≤ y < 0.10, 0 ≤z < 0.20) ceramics were investigated. The experimental results demonstrated that when x increases in Pb[Zr_(0.46)Ti_(0.54-x)(Zn_(1/3)Nb_(2/3))_x]O_3+0.3 mol%Fe_2O_3+0.5mol%K_2CO_3 ceramics, the d_(33), k_p, ε_r, and tgδ increase and approach to their maximum values, then eventually decrease. XRD analysis revealed that the perovskite structure of the materials transfers from tetragonal phase to rhombohedral phase. The relative dielectric constant (ε_r,) decreases dramatically in the rhombohedrai phase area near the MPB; the d_(33) and ε_r, decrease with the small amount of added Fe_2O_3 and K_2CO_3, which also contributes to densification of the PZN-PZT ceramics. The optimized piezoelectric performances through the experiment were obtained as d_(33)=280 pC/N, k_p=0.62, ε_r, =900, tgδ=0.003.