Extremely low loss and high electrical resistivity in CaBi2Nb2O9 high-temperature piezoelectric ceramic by adding WO3

An appropriate amount of WO ₃ was added into CaBi ₂Nb ₂O ₉ high-temperature piezoelectric ceramics to improve the dense microstructure and enhance the electrical properties. A portion of W ions can be incorporated into the lattice, resulting in an increase in the lattice distortion and spontaneous polarization. As a result, the ferroelectric and piezoelectric properties of the ceramics are promoted. Additionally, reducing the concentration of oxygen vacancies can increase the resistivity of ceramics and significantly reduce the dielectric loss. The CBNO-0.375 wt% WO ₃ sample shows a large piezoelectric coefficient of 17.1 pC/N, a high remnant polarization of 12.60 µC/cm ², a high T _C of 951°C and a large electrical resistivity of 1.86 × 10 ⁶ Ω·cm at 600 °C. Moreover, the dielectric loss at 600 °C maintains a low value of 0.0076, which is one to two orders of magnitude lower than that of CBNO-based ceramics. Therefore, the method of adding WO ₃ to construct a CBNO ceramic provides a new strategy for high-temperature piezoelectric applications.