Effects of the doping of W6+ ions on the structure and electrical properties of Pb0.95Ba0.05Nb2O6 piezoelectric ceramics

Abstract

The piezoelectric ceramics Pb0.95−xBa0.05(Nb1−xWx)2O6 with 2wt% excess PbO and 0.25wt% TiO2 (x=0, 0.025, 0.05, 0.075 and 0.1) were prepared by a conventional solid-state reaction method. Effects of the doping of W6+ ions on the crystallite structure, microstructure, dielectric and piezoelectric properties were studied in detail. The doping of W6+ ions improves the densification of the ceramics. X-ray diffraction patterns indicate that all ceramics form the single orthorhombic ferroelectric phase. The lattice parameters and grain size vary with the change of the W6+ contents. All ceramics exhibit the typical characteristic in ferroelectrics with normal ferroelectric–paraelectric phase transition at Curie temperature. Both Curie temperature and maximum dielectric constant are related to the W6+ amounts. The ceramic with x=0.075 possesses the high piezoelectric constant (d33, 108 pC/N), low mechanical quality factor (Qm, 29), low dielectric loss (tanδ, 0.006), and high Curie temperature (Tc, 448°C), presenting a high potential to be used in high-temperature applications as piezoelectric transducers.