NaCl/LiF添加剂对铌酸钾钠陶瓷相形成、介电性能和铁电性能的影响研究  

Effect of NaCl/LiF additive on phase formation,dielectric properties and ferroelectric properties of potassium sodium niobate ceramics

作　　者：孙健 SUN Jian(Chaozhou Third Ring(Group)Co.,Ltd.,Chaozhou Guangdong 521000,China)

机构地区：[1]潮州三环(集团)股份有限公司,广东潮州521000

出　　处：《当代化工》2022年第9期2118-2122,共5页Contemporary Chemical Industry

基　　金：潮州市科技计划项目,5G智能手机用陶瓷背板开发及产业化(项目编号:20180202)。

摘　　要：采用固态反应法制备了NaCl/LiF添加剂掺杂的(K_(0.5)Na_(0.5))NbO_(3)(KNN)无铅压电陶瓷。研究了NaCl/LiF添加剂(摩尔比为0.58∶0.42)对KNN陶瓷相形成、微观结构、介电性能和铁电性能的影响。X射线衍射表征结果表明,当NaCl/LiF添加剂掺杂量小于1%(摩尔分数)时,KNN陶瓷具有纯的四方钙钛矿结构,而当添加剂掺杂量大于1%(摩尔分数)后,在陶瓷样品的XRD谱图中观察到了杂峰,形成了杂质相。铁电性能研究结果表明,在初始KNN样品中,当温度为470 K时,正交相转变为四方相,在温度为650 K时,四方相转变为立方相。与初始KNN样品相比,NaCl/LiF添加剂改性陶瓷的相变温度有所升高,Tc值达到了约725 K。SHG的测量结果证明了NaCl/LiF添加剂的加入可以增强陶瓷的铁电性能,并提高Tc值。介电性能研究结果表明,掺杂1%(摩尔分数)NaCl/LiF添加剂的样品具有较好的电学性能(d_(33)=~207 pC/N,k_(p)=~0.421,k_(t)=0.424)和较高的力学品质因子(Q_(m)=288)。Lead-free(K_(0.5)Na_(0.5))NbO_(3)(KNN)piezoelectric ceramics doped with NaCl/LiF additive were prepared by solid-state reaction method.The effects of NaCl/LiF additive(molar ratio 0.58∶0.42)on the phase formation,microstructure,dielectric properties and ferroelectric properties of KNN ceramics were investigated.The X-ray diffraction results showed that KNN ceramics had pure tetragonal perovskite structure when the mole fraction of NaCl/LiF additive was less than 1%.However,when the doping amount of NaCl/LiF additive was more than 1%(mole fraction),impurity peaks were observed in the XRD pattern of the ceramic samples,forming impurity phase.The ferroelectric properties of KNN samples showed that at 470 K,the orthotropic phase transformed into tetetic phase,and at 650 K,the tetetic phase transformed into cubic phase.Compared with the initial KNN sample,the phase transition temperature of NaCl/LiF additive modified ceramics increased,and the T_(c) value reached about 725 K.The measurement results of SHG showed that the addition of NaCl/LiF could enhance the ferroelectric properties of ceramics and increase T_(c) value.The dielectric properties of the sample doped with 1%(mole fraction)NaCl/LiF had better electrical properties(d_(33)=~207 pC/N,k_(P)=~0.421,k_(t)=0.424)and higher mechanical quality factor(Q_(m)=288).

关 键 词：NaCl/LiF添加剂 铌酸钾钠陶瓷 介电 铁电 

分 类 号：TQ174[化学工程—陶瓷工业]