Two-Step Sintering of the Pure K_0.5Na_0.5NbO₃Lead-Free Piezoceramics and Its Piezoelectric Properties

Abstract

The two-step sintering method was successfully applied to fabricate the lead-free alkaline niobate (K0.5Na0.5NbO3) piezoelectric ceramics, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to characterize the samples. The properties of density, piezoelectric and ferroelectric were also investigated. Under the optimal sintering process, the specimens with the relative density 95.2%, which exhibit good electrical properties (d 33 = 121pC/N, k p = 35.2%, Q m = 5, ε r = 815). These results show that K0.5Na0.5NbO3 ceramic is a promising lead-free piezoelectric material for the ultrasonic delay-line applications, broadband transducers and sensors. The easy-controlling sintering process can be used in the other piezoelectric ceramics system.