Preparation and characterization of (K0.5Na0.5)NbO3 ceramics

In this paper the preparation and characterization of the ceramic material (K0.5Na0.5)NbO3 (KNN) has been studied. Although conventional processing of KNN is often reported to result in sintered bodies lacking sufficient density, samples produced in this work exhibit theoretical density over 95% and yield superior piezoelectric properties than those obtained by the same method and reported previously. The electromechanical coupling coefficient in the thickness direction, kt, is found to reach 45%. Apart from kt, the piezoelectric coefficients in longitudinal and planar directions (d33 of 100pC/N and d31 of 43pC/N), hysteresis loop, pyroelectric coefficient measurements and dielectric properties are presented.