Dielectric and piezoelectric properties of low temperature sintering PMN-PZT ceramics for multilayer piezoelectric transformer with $Li_2CO_3$ addition

적층 압전변압기용 저온소결 PMN-PZT 압전세라믹의 $Li_2CO_3$ 첨가에 따른 유전 및 압전특성

In this paper, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, PMN-PZT ceramcis using $Li_2CO_3$ and $Bi_2O_3$ as sintering aids were manufactured, and their microstructural, dielectric and piezoelectric properties were investigated. The sintering aids were proved to lower the sintering temperature of piezoelectric ceramics due to the effect of $LiBiO_2$ liquid phase. At 0.1wt% $Li_2CO_3$ added specimen sintered at $970[^{\circ}C]$, electromechanical coupling factor(Kp), mechanical quality factor(Qm) and dielectric constant showed the optimum values of 0.50, 2,413 and 1,245, respectively, for multilayer piezoelectric transformer application.