Effects of WO_3 addition on the structure and electrical properties of Pb_3O_4 modified PZT-PFW-PMN piezoelectric ceramics

摘要

The ceramics were prepared successfully by Pb_3O_4 and WO_3 additions to 0.90Pb(Zr,Ti)O_3-0.03Pb(Fe_(2/3)W_(1/3))O_3-0.07Pb(Mn_(1/3)Nb_(2/3))O_3 (0.90PZT-0.03PFW-0.07PMN). Effects of the additions on the structure, bulk density and electrical properties of ceramics were investigated. The results revealed that the proper additions of WO_3 with 2.0 wt.% Pb_3O_4 excess could form liquid phase that promoted the densification of the ceramics. The fracture mode changed from transgranular to intergranular as increasing WO_3 with 2.0 wt.% Pb_3O_4 excess. The piezoelectric and dielectric properties were also promoted by excess of Pb_3O_4 and WO_3 additions. The optimized electrical properties were obtained at excess of 2.0 wt.% Pb_3O_4 and 0.15 wt.% WO_3. The parameters were as follows: d_(33) = 351 pC/N, K_p = 0.64, Q_m = 1882, ε_r = 1798, tan δ = 0.0052, P_r = 19.94 μC/cm~2 and E_c = 11.98 kV/cm, which shows high K_p, Q_m, d_(33) and low tan δ can be obtained simultaneously by adding WO_3 addition to Pb_3O_4 modified PZT-PFW-PMN system.