K_(0.5)Na_(0.5)NbO_(3)-x LiNbO_(3)陶瓷的相转变与压电性能温度稳定性研究  

Study on Phase Transitional Behavior and Temperature Stability of Piezoelectric Properties of K_(0.5)Na_(0.5)NbO_(3)-x LiNbO_(3)Piezoelectric Ceramics

作　　者：肖荣振[1,2] 徐鹏 燕小斌[1,2] XIAO Rongzhen;XU Peng;YAN Xiaobin(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advance Processing and Recycling of Non-Ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学有色金属先进加工与再利用国家重点实验室,甘肃兰州730050

出　　处：《压电与声光》2024年第5期710-715,共6页Piezoelectrics & Acoustooptics

基　　金：甘肃省科技计划项目-联合科研基金重点项目(23JRRC0009)。

摘　　要：采用常规陶瓷工艺制备了K_(0.5)Na_(0.5)NbO_(3)-x LiNbO_(3)(KNN-x LN)基无铅压电陶瓷。采用介电温度谱结合XRD系统研究了铌酸锂(LN)掺杂对KNN陶瓷相结构与压电性能温度稳定性的影响规律与机制。结果表明,LN在KNN陶瓷中的固溶度范围内(约小于10%(摩尔分数)),LN掺杂具有同时提升KNN陶瓷的T_(C)与降低陶瓷T_(O-T)的效应。当LN的掺杂量(摩尔分数)为6%时,可使陶瓷的T_(O-T)下移至室温,此时陶瓷为正交相与四方相两相共存,陶瓷的压电性能得到极大增强。T_(C)的提升增强了陶瓷的压电性能温度稳定性,当LN的掺杂量(摩尔分数)x~8%,T_(C)增加至479℃,此组分陶瓷的压电性能经470℃热处理后仍保持在室温时的71%,表现出良好的温度稳定性。当LN超过固溶度后,部分LN倾向于与K元素生成第二相,未反应的LN因其强热释电效应导致陶瓷的d 33呈现出随热处理温度升高而增强的伪增强趋势。In this study,lead-free piezoelectric ceramics,based on the K_(0.5)Na_(0.5)NbO_(3)-x LiNbO_(3)(KNN-x LN)system,were fabricated using a conventional method.The influence and mechanism of lithium niobate(LN)doping on the phase structure and temperature-dependent piezoelectric properties of KNN ceramics were meticulously investigated through dielectric temperature spectroscopy and X-ray diffraction(XRD)analysis.Our findings reveal that LN has a solubility limit in KNN of less than 10 mol%.Within this limit,incorporating LN induces a shift in the Curie temperature(T_(C))of KNN-x LN ceramics toward higher temperatures,while the transition from orthorhombic to tetragonal phases(T_(O-T))is pushed to lower temperatures simultaneously.At room temperature,the ceramics exhibit the coexistence of orthorhombic and tetragonal phases,significantly amplifying their piezoelectric performance.An elevated T_(C)improves the temperature stability of the ceramics’piezoelectric properties;specifically,with an LN doping level of approximately 8 mol%,T_(C)reaches approximately 479℃,and the piezoelectric properties of this componenT_(C)eramic after 470℃heat treatment remain 71%at room temperature.Beyond the solubility threshold,excess LN is prone to forming a secondary phase with potassium,and the residual LN,influenced by its pronounced pyroelectric effect,results in an apparent increase in the d 33 coefficient of the ceramics as the heat treatment temperature increases.

关 键 词：铌酸钾钠 铌酸锂 相结构 居里温度 压电性能温度稳定性 

分 类 号：TM282[一般工业技术—材料科学与工程] TN384[电气工程—电工理论与新技术]