Effect of sintering temperature and time on densification, microstructure and properties of the PZT/ZnO nanowhisker piezoelectric composites

Lead zirconate titanate (PZT) based piezoelectric composites embedded with ZnO nanowhiskers (ZnOw) were investigated to clarify the optimal sintering condition for densification, microstructure, and electrical properties. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The results show that the increase of the sintering temperature and time is quite effective in improving the densification and piezoelectric properties of the PZT/ZnOw composites. However, the relative density and piezoelectric properties deteriorate as the composites are sintered over the optimal sintering condition. Particularly, the PZT/ZnOw composites sintered at 1150 °C for 2 h show excellent electrical properties of piezoelectric constant d33 ∼ 471 pC/N, relative dielectric constant ɛ ∼ 3838, planar electromechanical coupling factor kp ∼ 0.543, remnant polarization Pr ∼ 23.2 μC/cm2 and coercive field Ec ∼ 9.2 kV/cm.

► The increase of sintering temperature and time enhances the grain growth, densification and electrical properties of the PZT/ZnOw composites in effect.
► The PZT/ZnOw composites with 2 wt.% ZnOw sintered at 1150 °C for 2 h shows the optimal density and electrical properties.
► The temperature and time stability of the PZT/ZnOw composites are quite good, suggesting that the new PZT/ZnOw composites are promising candidates for practical applications.