摘要
采用固相反应法制备了MnO2掺杂Sr1.95Ca0.05NaNb5O15+ywt%MnO2(SCNNM)无铅压电陶瓷。研究了MnO2掺杂对SCNNM陶瓷显微结构及电学性能的影响。结果表明:当y≤0.7时,SCNNM陶瓷为单一的四方钨青铜结构,当y≥1.0时有第二相生成;少量MnO2掺杂能有效降低烧结温度,促进晶粒长大,显著提高SCNNM陶瓷的介电、压电性能,降低矫顽场和居里温度,当y>0.7时,陶瓷烧结恶化,性能降低。当y=0.5时,SCNNM陶瓷具有较好的介电、压电和铁电性能:介电系数εr=2123,介电损耗tanδ=0.038,平面伸缩振动机电耦合系数Kp=13.4%,厚度伸缩振动机电耦合系数Kt=36.5%,矫顽场Ec=12.68 kV/cm,剩余极化强度Pr=4.76μC/cm2,压电系数d33=190 pC/N,机械品质引因数Qm=1455,居里温度Tc=260oC。
Piezoelectric ceramics Sr1.95Ca0.05NaNb5O15＋y wt%MnO2（SCNNM） with y ranging from 0 to 1.5 were prepared by solid-state reaction method.The results indicated that the calcined SCNNM ceramics retain a single phase of tetragonal tungsten-bronze structure with y≤0.7.When y≥1.0,a secondary phase was observed.The addition of a little MnO2 could decrease the sintering temperature,promote grain growth.The dielectric,piezoelectric and ferroelectric properties of the SCNNM ceramics significantly increased.At room temperature,the SCNNM ceramic with y=0.5 exhibits the optimum properties： piezoelectric coefficient d33=190 pC/N,mechanical quality factor Qm=1455,planer and thickness electromechanical coupling factors Kp=13.4% and Kt=36.5%,dielectric constant εr=2123,loss tangent tanδ=0.038,remanent polarization Pr=4.76 μC/cm2,coercive field Ec=12.68 kV/cm,and curie temperature Tc=260 oC.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2011年第3期639-644,656,共7页
Journal of Synthetic Crystals
基金
北京市教委基金资助项目(JC00615200901)
