실험계획법을 적용한 무연 (Na1/2K1/2)NbO3세라믹스의 CuO 및 MnO2첨가에 따른 압전 및 유전 특성

Abstract

Lead-free piezoelectric (<TEX>$Na_{1/2}K_{1/2}$</TEX>)<TEX>$NbO_3$</TEX> ceramics doped with CuO and <TEX>$MnO_2$</TEX> were fabricated using the conventional oxide-mixing technique. With increasing content of CuO and <TEX>$MnO_2$</TEX>, the dielectric constant(<TEX>${\varepsilon}_{33}$</TEX>) and mechanical quality factor(<TEX>$Q_m$</TEX>) value increased, while electromechanical coupling factor(<TEX>$K_p$</TEX>) and piezoelectric constant(<TEX>$d_{33}$</TEX>) decreased. The piezoelectric and dielectric properties (<TEX>$Na_{1/2}K_{1/2}$</TEX>)<TEX>$NbO_3$</TEX> ceramics doped with CuO 2.461 wt% and <TEX>$MnO_2$</TEX> 0.538 wt% at sintered temperature <TEX>$1050\;^{\circ}C$</TEX> were attained <TEX>${\varepsilon}_{33}$</TEX> = 403, <TEX>$K_p$</TEX> = 15, <TEX>$Q_m$</TEX> = 122 and <TEX>$d_{33}$</TEX> = 36 pC/N. Based on response surface methodology results using design of experiment, it was concluded that (<TEX>$Na_{1/2}K_{1/2}$</TEX>)<TEX>$NbO_3$</TEX> doped with CuO 0.477 wt% and <TEX>$MnO_2$</TEX> 0.269 wt% has possibility composition of being used for piezoelectric transformer.