铌酸钾钠基无铅透明陶瓷制备及性能

采用传统固相烧结工艺, 结合特殊的气氛控制技术,制备了铌酸钾钠(KNN)基无铅透明陶瓷 xBa(Sc_0.5Nb_0.5)O₃-(1-x) (K_0.5N_0.5)NbO₃ (简写xBSN-(1-x)KNN). 并对其微观结构、介电、铁电性能和光学透光率进行了研究. 结果表明该体系陶瓷具有准立方钙钛矿结构, 没有其他杂相, 晶粒大小与可见光波长相当, 高度致密, 无明显的晶界存在. 在 x=0.05时, d₃₃最高可达到110 pC/N, 2P_r达到25.4 μC/cm². 同时该材料具有良好的透明性, 在可见光范围内,透过率达到54%左右, 近红外2500 nm处,透过率接近83%, 是一种有望取代铅基透明陶瓷的环境友好型无铅透明陶瓷.

Preparation and performances of KNN-based lead-free transparent ceramics

Using conventional solid-phase sintering technique combined with a special atmosphere controlling technique, KNN-based lead-free transparent ceramics, xBa(Sc_0.5Nb_0.5)O₃-(1-x) (K_0.5N_0.5)NbO₃ (xBSN-(1-x) KNN), are prepared and investigated. Their microstructure, dielectric performance, ferroelectric performance and optical transparency are investigated. The results show that such ceramics are each with a pseudocubic-Perovskite structure, without any other impure phase. Their grain size is comparable to the light wavelength and the grains are highly condensed without evident crystal borders. For x=0.05, the d₃₃ reaches up to 110 pC/N maximally and the 2P_r =25.4 μC/cm². Moreover, such ceramics are each with an excellent transparency. Their optical transparency reaches about 54%, In the near-infrared wavelength 2500 nm, their optical transparency is near 83%. Such ceramics are a type of environment-friendly lead-free transparent ceramics which may be promising in replacing lead-based transparent ceramics.