摘要
利用高温高压法制备了具有正交钙钛矿结构的KNb0 9Mg0 1 O3 a固体电解质。阻抗谱分析发现 ,样品的晶界效应比较明显 ,电导率主要取决于晶界电导。根据测得的阻抗谱 ,提出了等效电路。通过对阻抗谱数据进行拟合 ,获得了晶粒、晶界及总电导率。在测量温度范围内 ,电导率与温度成线性关系 ,满足Arrhenius经验公式。Mg2 + 掺杂显著提高了样品的电性能 ,70 0℃时KNb0 9Mg0 1 O3-a的氧离子电导率为 1 2× 10 - 3S cm。
The solid electrolyte KNb_ 0.9 Mg_ 0.1 O_ 3- a with orthorhombic perovskite structure was prepared with high temperature and high pressure method.The impedance spectrum analyses showed that the grain-boundary effect was very obvious and the electrical conductivity was controlled by grain-boundary processes.Equivalent circuit was proposed according to the measured impedance spectrum.By fitting the impedance data,we obtained the grain,grain-boundary and total ionic conductivity of KNb_ 0.9 Mg_ 0.1 O_ 3- a .The temperature dependence of conductivity was linear in the measured temperature range,which satisfied the Arrhenius empirical formula.Mg-doping improved the electrical properties of the sample significantly.The conductivity of KNb_ 0.9 Mg_ 0.1 O_ 3- a is 1.2×10 -3 S/cm at 700℃.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2004年第3期393-396,共4页
Journal of Materials Science and Engineering
