Gd3+掺杂调控BiFeO3-BaTiO3高温无铅压电陶瓷的结构与性能
Structures and properties of Gd3+ doped modified BiFeO3-BaTiO3 high-temperature lead-free piezoelectric ceramics
唐蓝馨 1王芳 1周治 1李双池 1左鑫 1李凌峰 1杨柳 1谭启 2陈渝1
作者信息
- 1. 成都大学 机械工程学院,成都 610106
- 2. 广东以色列理工学院材料科学与工程系,广东 汕头 515063
- 折叠
摘要
用于监测航空发动机、重型燃气轮机等重大技术装备高温部件振动状态的压电加速度传感器,需要一种高居里温度压电陶瓷作为敏感元件,而电子元器件的无铅化是环境保护的迫切要求.采用传统的固相反应法制备一种Gd/Mn共掺杂的BF-BT((0.67BiFeO3-0.33Ba1-xGdxTiO3)+0.5%(质量分数)MnO2,x=0～0.02)高温无铅压电陶瓷,并研究Gd3+掺杂浓度(x)对BF-BT陶瓷的相组成、微观结构、压电性能、介电弛豫行为及交流阻抗特征的影响.结果表明:所有样品均为单一钙钛矿结构,三方相(R)和四方相(T)共存,且T相含量随x增加而增加;适量的Gd3+(x<0.02)固溶进入钙钛矿点阵之中能够促进BF-BT陶瓷晶粒的生长.掺杂Gd3+的样品表现出增强的弛豫相变行为,相变温度(Tm)随x的增加而减小,而介电弛豫程度(ΔTrelax)随x的增加而增大.采用R-CPE等效电路模型对BF-BT陶瓷的高温复阻抗谱(Cole-Cole图)进行拟合分析,发现样品在高温下的交流阻抗主要来自晶界的贡献.并且随着Gd3+掺杂浓度的提高,样品的介电弛豫激活能不断增大,证实Gd3+取代Ba2+减少了晶格中氧空位浓度的施主掺杂效应.综合来看,x=0.01的样品具有最优的电学性能:TC=425℃,d33=126 pC/N,kp=25.9%,tanδ=0.059,有望作为一种合适的高温压电材料被应用.
Abstract
Piezoelectric acceleration sensors are used for monitoring the vibration state of high-temperature components of some important technical equipment,such as aero engines and heavy gas turbines.These sensors require a high Curie temperature piezoelectric ceramic as a sensitive element,and"lead-free"electronic components are an urgent requirement for environmental protection.Gd/Mn co-doped high-temperature lead-free piezoelectric ceramics((0.67BiFeO3-0.33Ba1-xGdxTiO3)+0.5%(mass fraction)MnO2,x=0-0.02,BF-BT)were prepared by a traditional solid-state reaction process.The effects of doping concentration x of Gd3+ on the phase composition,microstructure,piezoelectric property,dielectric relaxation behavior and AC impedance characteristic of BF-BTceramics were investigated.The results show that all samples have pure perovskite structure with coexistence of tripartite phase(R)and tetragonal phase(T),and the T phase content increases with the increasing Gd3+ doping concentration.Moderate amount(x<0.02)of Gd3+ dopant diffusing into the perovskite lattice would also promote the grain growth of BF-BT ceramics.Gd3+ doped samples exhibit enhanced relaxation phase transition behavior.The phase transition temperature(Tm)decreases with the increase of x,while the dielectric relaxation degree(ΔTrelax)increases with the increase of x.The R-CPE equivalent circuit model has been utilized to match the complex impedance spectra(Cole-Cole diagrams)of the BF-BTceramics,indicating that the AC impedance of samples at high temperature is mainly contributed by the grain boundary.The activation energy of dielectric relaxation increases with the increasing Gd3+ doping concentration,demonstrating the substitution of Gd3+ for Ba2+ can reduce the donor doping effect.In general,when x=0.01,the sample exhibits the optimized electrical properties,including TC=425℃,d33=126 pC/N,kp=25.9%,and tanδ=0.059.The Gd3+ doped BF-BTceramics are expected to be used as a promising high-temperature piezoelectric material.
关键词
BiFeO3-BaTiO3/高温无铅压电陶瓷/离子掺杂/介电弛豫/交流阻抗Key words
BiFeO3-BaTiO3/high-temperature lead-free piezoelectric ceramics/ion doping/dielectric relax-ation/AC impedance引用本文复制引用
基金项目
机械结构力学与控制国家重点实验室开放课题(MCMS-E-0522G01)
四川省自然科学基金(2022NSFSC1968)
广东省能量转换材料与技术重点实验室开放基金(MATEC2022KF001)
四川省大学生创新创业训练计划项目(S202311079053)
出版年
2024
国家科技期刊平台
NSTL
万方数据