산화물 첨가제에 의한 친환경 압전세라믹스의 특성연구 = Oxide Doping Effect of Eco-friendly Piezoelectric Ceramics

다국어 초록 (Multilingual Abstract)

PZT-based piezoelectric ceramics at domestic and abroad as a key raw material being used, but according to recent greening, lead-free systems have been actively investigated. In this study, the well known Li-NKN system, [(K0.5Na0.5)0.925Li0.075]NbO3 was selected as the basic lead-free piezoelectric composition. And (K0.5Na0.5)0.925-XLi0.075ZnX](Nb1-XTiX)O3 (0≤x≤0.05) specimens were prepared by doping Zn(+2) and Ti(+4) oxides simultaneously. Their crystal structures, microstructures, dielectric and piezoelectric properties were investigated with different dopant contents and sintering temperatures. For all specimens, a typical perovskite structure with a trace of secondary phase identified as K3Li2Nb5O15 was observed. Sinterability was apparently changed with doping concentration and sintering temperature. Maximum density was obtained by adding 2.5 mol% Zn/Ti (x=0.025) and sintering at 1000 oC for 2 h. At that condition, relatively improved ɛr, 940 and Qm, 141 were observed. However, kp and d33 values are ∼31%(kp) and ∼28%(d33) lower compared to those of undoped NKLN ceramics, which suggest that the Zn/Ti is a good hardner dopant for NKLN ceramics.