Effect of Ta Doping on Piezoelectric Properties of Lead-Free (K0.5Na0.5)NbO3Ceramics

We investigated the effect of Ta doping on the dielectric and piezoelectric properties of lead-free (K0.5Na0.5)NbO3 ceramics prepared using a conventional ceramic processing. X-ray diffraction analysis revealed that Ta was perfectly substituted into Nb-sites in the range of 0 to 20 at%. As Ta content in the KNN increased, the sinterability of KNN ceramics was significantly degraded while the Ta doping enhanced the piezoelectric constant d33, planar mode piezoelectric coupling coefficient (kp), and electromechanical quality factor (Qm). The highest values for d33, kp, and Qm was found to be 156 pC/N, 0.37, and 155, respectively.