We investigated the sintering behavior and piezoelectric properties of lead-free (K0.5Na0.5)NbO3 ceramics co-doped with excess 0.01 mol ZnO and x mol MnO2, where x was varied from 0 to 0.03. Excess MnO2 addition was found to retard the grain growth and densification during sintering. However, 0.005 mol MnO2 addition improved the piezoelectric properties of 0.01 mol ZnO added (K0.5Na0.5)NbO3 ceramics. The planar mode piezoelectric coupling coefficient, electromechanical quality factor, and piezoelectric constant d33 of 0.01 mol ZnO and 0.005 mol MnO2 added specimen were 0.40, 304, and 214 pC/N, respectively.

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

Citations

• Selection and optimization of Sb and Ta co-doped (K0.41Na0.59)(Nb1-x-ySbxTay)O3 lead-free ceramics
  Le Tran Uyen Tu, Nguyen Truong Tho
  Journal of Materials Science: Materials in Electronics.2023;[Epub]     CrossRef