LiF掺杂对BiFeO_(3)-BaTiO_(3)陶瓷结构、铁电和压电性能的影响  

Effect of LiF doping on structure,ferroelectric and piezoelectric properties of BiFeO_(3)-BaTiO_(3)ceramics

作　　者：何秀将 王昕阳 何新华[1] 王歆[1] 卢振亚[1] HE Xiujiang;WANG Xinyang;HE Xinhua;WANG Xin;LU Zhenya(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学材料科学与工程学院,广州510641

出　　处：《材料工程》2023年第6期46-51,共6页Journal of Materials Engineering

基　　金：广东省重点领域研发计划项目(2020B0109380001)。

摘　　要：采用固相反应法制备0.7BiFeO_(3)-0.3BaTiO_(3)+0.35%(摩尔分数,下同)MnO_(2)+x%LiF(BF-BT-MN-x LF)压电陶瓷。采用XRD,SEM,铁电测试系统和精密阻抗分析仪测试陶瓷的物相组成、显微结构和铁电、压电性能。结果表明:LiF掺杂加强晶格畸变,促进烧结和晶粒生长,改善压电性能的温度稳定性。Li^(+)和F-不等价取代A/B位产生的复合缺陷偶极子,转向速度滞后于外加电场的变化,导致电滞回线呈现夹持现象。同时,对BF-BT-MN-x LF陶瓷的退极化行为以及居里温度变化的研究表明,LiF掺杂显著提高陶瓷的居里温度T c和退极化温度T_(d),T_(c)和T_(d)分别由500℃和410℃(x=0)升高到550℃和505℃(x=0.50)。当LiF掺杂量为0.50%时,在860~1020℃温度范围内烧结的陶瓷始终保持较高的压电系数,d_(33)=176~202 pC/N。x=0.50的陶瓷样品在960℃烧结表现出最佳的压电性能:d_(33)=202 pC/N,k_(p)=34%,T_(c)≈550℃,T_(d1)≈505℃。0.7BiFeO 3-0.3BaTiO 3+0.35%(mole fraction,the same below)MnO 2+x%LiF piezoelectric ceramics(BF-BT-MN-x LF)were synthesized via a solid state reaction process.The phase composition,microstructure,ferroelectric and piezoelectric properties of BF-BT-MN-x LF ceramics were measured by XRD,SEM,ferroelectric test system and precision impedance analyzer.The results indicate that LiF doping enhances lattice distortion,promotes sintering and grain growth,as well as the temperature stability of piezoelectric performance.The orientation of the composite defect dipoles produced by the inequivalent substitution of Li^(+)and F-for A/B site,lags behind the changes in the electric field,and consequently brings about a clamping hysteresis loop.Meanwhile,the investigation on the depolarization behavior and Curie temperature for BF-BT-MN-x LF ceramics reveals that both Curie temperature T_(c)and depolarization temperature T_(d)increase remarkably,and T_(c)and T_(d)increase from 500℃and 410℃(x=0)to 550℃and 505℃(x=0.50),respectively.When the doping amount of LiF is 0.50%,the ceramics sintered at 860-1020℃,maintain excellent piezoelectric activity with a high d_(33)value of 176-202 pC/N.The ceramics with x=0.50 sintered at 960℃show the optimum piezoelectric properties:d_(33)=202 pC/N,k p=34%,T_(c)≈550℃,T_(d1)≈505℃.

关 键 词：BiFeO_(3)-BaTiO_(3) 无铅 LiF掺杂 压电性能 铁电性能 

分 类 号：TM282[一般工业技术—材料科学与工程]