Structural and electrical properties of W6+-doped Bi3TiNbO9 high-temperature piezoceramics

High-temperature piezoceramics based on W6+-doped Bi3TiNbO9 (BTNO) were prepared by solid-state reaction sintering. A study of the donor doping effects on the structure, microstructure, and electrical properties was conducted. The Curie point (T-c) decreased in the range of 860 degrees-910 degrees C with increasing amount of W(6+)doping. W6+ donor dopant decreased the conductivity in BTNO by as much as two orders of magnitude. The increased resistivity in W6+-doped BTNO induced the materials to be polarized under a high enough field. The highest piezoelectric constant, d(33), of 12.0 pC/N was achieved with the composition of Bi3Ti0.99W0.01NbO9. Also, this composition had a good thermal depoling resistance property.