High Piezoelectricity in Lead-Free Piezoelectric Ceramics from View Points of Young's Modulus and Poisson's Ratio

Abstract

Evaluation on ferroelectric domain structures is described in piezoelectric ceramics composed of alkali bismuth niobate and alkali bismuth titanate. Ferroelectric domain switching and domain rotation could be explained by DC poling field dependence of dielectric piezoelectric prpperties. In addition, Young's modulus and Poisson's ratio toward poling field in piezoelectric ceramics were investigated by measuring longitudinal and transverse acoustic wave velocities to clarify the relationships between high piezoelectricity and the values. Basically, increasing domain alignment by applying DC poling field, the Young's modulus decreased and Possion's ratio increasd.