HE Qiang 1, 2, NIE Jingkai 1, HAN Yu 1, GENG Jinfeng 3, CUI Jianye 4, TIAN Yi 1, MI Lipeng 5
(1. State Grid Smart Grid Research Institute Co. Ltd., Beijing 102209; 2. North China Electric Power University, School of Energy, Power and Mechanical Engineering, Beijing 102206; 3. State Grid Henan Electric Power Research Institute, Zhengzhou 450052, Henan, China; 4. Jinhua Power Supply Company, State Grid Zhejiang Electric Power Co. Ltd., Jinhua 321000, Zhejiang, China; 5. State Grid East Inner Mongolia Electric Power Research Institute, Hohhot 010020, Inner Mongolia, China)
Abstract: (K0.4825Na0.4825Li0.035)(Nb0.8Ta0.2)O3(KNLNT) lead-freee piezoelectric ceramics doped with different concentrations of Ge4+ were prepared by using the conventional ceramic processing. The effects of Ge4+ doping on sintering and electrical properties of the KNLNT ceramics were studied. It was found that Ge4+doping can decrease the sintering temperature and reduce the volatilization of alkali metallic (in particular lithium) elements. Ge4+ substitution at B-site not only facilitates the solid solution of Li+ into the perovskite structure, but also improves the uniformity of chemical composition. Lead-free piezoelectric KNLNT ceramics with promising sinterability and piezoelectric properties (d33~220 pC•N−1) were obtained when 0.2% Ge4+ was added.
Key words: lead-free piezoelectric ceramics; potassium sodium niobate; low-temperature sintering; acceptor doping