Effects of NbO addition on the microstructure, electrical, and mechanical properties of PZT/ZnO nanowhisker piezoelectric composites.

NbO-modified PZT/ZnO nanowhisker (denoted as PZT/ZnO-NbO) piezoelectric composites were prepared by a solid state sintering technique. Effects of NbO addition on the microstructure, electrical, and mechanical properties of the PZT/ZnO composites were investigated. With increasing NbO content, the grain size of the composites was reduced and the fracture mode changed from intergranular to intragranular gradually. Compared with the PZT/ZnO composites, the dielectric, piezoelectric, and ferroelectric properties of the PZT/ZnO-NbO composites were improved significantly, while mechanical properties were enhanced slightly. The optimum electrical and mechanical properties were achieved for the PZT/ZnO composites modified with 0.75 wt% NbO sintered at 1150 °C, with dielectric permittivity ε, piezoelectric coefficient d, planar electromechanical coupling k, remnant polarization P, fracture toughness K, and flexural strength σ being on the order of 4930, 600 pC/N, 0.63, 29.2 μC/cm, 1.56 MPa m and 130 MPa, respectively. The NbO-modified PZT/ZnO piezoelectric composites, with comparable electrical properties and improved mechanical properties than those of commercial PZT-5H ceramics, are promising candidates for further applications. [ABSTRACT FROM AUTHOR]