钇铁共掺杂锆酸钙致密扩散层极限电流型氧传感器

Limiting Current Oxygen Sensor Based on Y, Fe co-doped CaZrO-based Materials As Dense Diffusion Barrier Layer

采用固相反应法合成钇铁共掺杂锆酸钙(Y0.08Ca0.92Zr1-xFexO3-δ(x=0.3,0.4,0.5))混合导体材料,以钇铁共掺杂锆酸钙为致密扩散障碍层,以YSZ为泵氧层,制备了极限电流氧传感器。结果表明:Y0.08Ca0.92Zr1-xFexO3-δ的主晶相为菱方钙钛矿结构;随Fe掺杂量的增加,Y0.08Ca0.92Zr1-xFexO3-δ材料的总电导率和离子电导率均增大;在800~950℃范围,氧传感器具有良好的极限电流,出现极限电流的温度随Fe掺杂量的增加而降低,极限电流(lg IL)与1 000/T呈线性关系:lg IL=3.215-2.101 3×(1 000/T),氧离子扩散激活能为0.417 eV。在750℃、1.0%(摩尔分数)≤x(O2)≤7.5%时,极限电流IL与氧含量x(O2)间的关系式为:IL=7.047 6+3.875 1×x(O2)。

Y-, Fe co-doped CaZrO3(Y0.08Ca0.92Zr1-xFexO3-δ(x=0.3,0.4,0.5)) was synthesized by solid state reaction method. The crystal phase composition, microstructure, oxygen ionic conductivity, total conductivity and sensing properties were investigated. The result suggests that a highly orthorhombic perovskite structure and the increase of Fe-doped amount is unfavorable for the formation of single orthorhombic perovskite structre. The total electrical conductivity and ionic conductivity increase with Fe-doped amount increasing. The oxygen sensor shows good limiting current plateau in the range of 800-950 ℃. The linear relationship between limiting current(lgIL) and 1 000/T can described as follows: lgIL =3.215-2.101 3×(1 000/T)and the activation energy of oxygen ion is 0.417 e V. At 750 ℃、1.0%≤x(O2)≤7.5%,the relationship between limiting current(IL) and oxygen amount(x(O2)) can be expressed:IL= 7.047 6+3.875 1×x(O2).