8.K0.5Na0.5NbO3-BaZrO3无铅压电陶瓷结构和电学性能

袁志¹，苏红波²，梅早明³，吴枚霞⁴，刘来君^4*

（1.桂林航天工业学院能源与建筑环境学院，桂林，541004;2.河南省产品质量监督检验院，郑州，450003;3. 河南力恒建材有限公司，郑州，450001;4.桂林理工大学材料科学与工程学院，桂林，541004）

关键词：无铅压电陶瓷；铌酸钾钠；锆酸钡；相变

中图分类号：TM282              文献标识码：A

摘要:采用固相法制备(1-x)K_0.5Na_0.5NbO₃-xBaZrO₃（x=0.02，0.06，0.08，0.11，0.13）无铅压电陶瓷，研究BaZrO₃掺杂量对K_0.5Na_0.5NbO3陶瓷相结构、微观形貌和电性能的影响。结果表明：所有陶瓷均为为纯钙钛矿结构，随着BaZrO₃掺杂量的增加，陶瓷由正交相（x≤0.02）转变为三方–四方两相共存（x=0.06），再转变为赝立方相。BaZrO₃的增加引起样品的居里温度降低，介电峰变得宽化，表现出典型弛豫铁电体的特征。在两相共存区x=0.06时，样品的压电性能最好：d₃₃=101 pC/N，k_p=0.284。另外，在相变点x=0.06处，剩余极化强度和矫顽场都取得最小值：P_r=4.1μC/cm²，E_c=0.95kV/mm。

Structure andElectrical Properties of K_0.5Na_0.5NbO₃-BaZrO₃Lead-free Piezoelectric Ceramics

YUAN Zhi¹, SU Hongbo²,MEI Zaoming³, WU Meixia⁴, LIU Laijun^*

(1.Collage of Energy and Building Environment, Guilin University Of AerospaceTechnology, Guilin, 541005, China; 2. Henan Province Product QualitySupervision and Inspection Center, Zhengzhou, 450003, China; 3. Henan LiHengBuilding Materials Co., Ltd., Zhengzhou, 450001, China; 4. School of MaterialsScience and Engineering, Guilin University of Technology, Guilin 541004, P.R.China)

Keywords:lead-free piezoelectric ceramics; potassium sodium niobate; bariumzirconate;phase transition

Abstract: (1-x)K_0.5Na_0.5NbO₃-xBaZrO₃(x=0.02, 0.06, 0.08, 0.11 and 0.13) lead-free piezoelectric ceramicswere prepared via a solid state reaction method. The effect of BaZrO₃doping amount x on the crystal structure, microstructure and electricalproperties of the ceramics was investigated. The results indicate that all thesamples possess a pure perovskite structure. The phase structure of theceramics gradually changes from the orthorhombic (x≤0.02) tocoexisted rhombohedral and tetragonal phases (x=0.06) ,thento pseudo-cubicphase. The increase of BaZrO₃ results in an decrease of Curietemperature andthebroadening of dielectricpeaks, showingferroelectric relaxor behavior.For x=0.06, the best performance was obtainedas follows:piezoelectric coefficient d₃₃=101 pC/N, planar electromechanical coupling k_p=0.284;in addition, both theremnant polarization P_r=4.1μC/cm² and the coercivefield E_c=0.95kV/mm are the lowest.