Dielectric and Piezoelectric Characteristics of $0.95(K_{0.5}Na_{0.5})NbO_3$-0.05Li$(Sb_{0.8}Nb_{0.2})O_3$ Ceramics with the amount of $MnO_2$ addition

$MnO_2$ 첨가에 따른 $0.95(K_{0.5}Na_{0.5})NbO_3$-0.05Li$(Sb_{0.8}Nb_{0.2})O_3$ 세라믹스의 유전 및 압전특성

In this study, $0.95(K_{0.5}Na_{0.5})NbO_3$-0.05Li$(Sb_{0.8}Nb_{0.2})O_3$ + $Ag_2O$ + x wt% $MnO_2$ were investigated as a function of the amount of $MnO_2$ addition in order to improve dielectric and piezoelectric properties of Lead-free piezoelectric ceramics. With increasing the amount of $MnO_2$ addition, density and electromechanical coupling factor $(k_p)$ increased up to 0.3wt.% $MnO_2$ and decreased above 0.3wt.% $MnO_2$. At the sintering temperature of 1020 $^{\circ}C$, Electromechanical coupling factor $(k_p)$, density, dielectric constant $({\varepsilon}r)$ and mechanical quality factor $(Q_m)$ of composition ceramics with 0.4wt% $Ag_2O$ addition showed the optimal value of 0.431, 4.33 g/$cm^3$, 820 and 119, respectively.