Piezoelectric properties and conductivity of Pb(Zr,Ti)O3 with SrO–WO3 additive.

The influence of SrO–WO₃ additive on the piezoelectric properties and electric conductivity of lead zirconate–titanate (PZT) near the morphotropic phase boundary was investigated. Starting from the composition 0.995 Pb(Zr_0.525Ti_0.475)O₃ + 0.015 SrO + 0.005 WO₃ (corresponding to 0.5 mol% of Sr₃WO₆) the fraction of WO₃ was increased until Sr:W = 1:1. These samples were compared to a set of samples of PZT with WO₃ addition but without SrO. Sr₃WO₆ has pseudocubic K₂NaAlF₆ structure with part of the strontium being octahedrally coordinated. In a solid solution with PZT this opens the possibility of realizing Sr on a B-site adjacent to a B-site occupied by W. Piezoelectric properties were measured on sintered disc samples under high field conditions. Impedance spectroscopy was used to investigate the conductivity and dielectric properties of the ceramics at various temperatures. The combined addition of SrO and WO₃ increases the piezoelectric strain compared to samples of PZT with WO₃ addition only. The results in polarization and conductivity indicate that the donor effect of WO₃ is counteracted by the addition of SrO. [ABSTRACT FROM AUTHOR]