BiScO3 Doped (Na0.5K0.5)NbO3 lead-free piezoelectric ceramics

Abstract

Lead-free potassium sodium niobate-based piezoelectric ceramics (1-x)(Na0.5K0.5)NbO3-xBiScO3 (KNN-BS) (x=0∼0.05) have been prepared by an ordinary sintering process. Single perovskite phase of KNN-BS exhibits an orthorhombic symmetry at x<0.015 and pseudocubic symmetry at x>0.02, separating by a MPB at 0.015≤x≤0.02. Piezoelectric and ferroelectric properties are significantly enhanced in the MPB, which are as follows: piezoelectric constant d 33=203 pC/N, planar coupling coefficient kp=0.36, remnant polarization Pr=24.4 μC/cm2. These solid solution ceramics look promising as a potential lead-free candidate materials. © 2008 The American Ceramic Society.