Shear-Mode Piezoelectric Properties of KNbO3-Based Ferroelectric Ceramics

Potassium niobate, KNbO 3 , (KN)-based ceramics were prepared by a modified conventional ceramic fabrication process to characterize their piezoelectric properties. The KN–MnCO 3 0.1 wt % (KN–Mn0.1) ceramic used in this study showed a high density ratio >96% and a high resistivity, ρ, of about 10 13 Ω·cm without deliquescent properties. The shear mode of the KN–Mn0.1 ceramic showed excellent resonance and antiresonance characteristics with tiny spurious peaks upon optimization of the sample dimensions. The electromechanical coupling factor, k 15 , and piezoelectric strain constant, d 15 , of KN–Mn0.1 showed relatively large values of 0.55 and 207 pC/N, respectively. The shear-mode vibration of KN-based ceramics appears to be a very promising candidate for actuators and high-power applications.