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.
In this study, piezoelectric and dielectric properties of Lead-free 0.97[(K0.5Na0.5)(Nb0.97Sb0.03)O3] + 0.03[(Bi0.5K0.5)TiO3] (abbreviated as 0.97NKNS-0.03BKT)ceramics synthesized by conventional solid-state reaction process were investigated as a function of K5.4Cu1.3Ta10O29 addition. The results indicated that the K5.4Cu1.3Ta10O29 addition significantly improved the sinterability, grain growth and piezoelctric properties of 0.97NKNS-0.03BKT ceramics. The optimum values as planar piezoelectric coupling coefficient (kp= 0.355), piezoelectric constant (d33= 207 pC/N) and mechanical quality factor (Qm= 128) were obtained when 0.009KCT was added. The electromechanical coupling factor(kp )was slightly decreased according to the increasing temperature.
First
Prev
