掺杂BaCeO_3和SrCeO_3在氧、氢及水气气氛下的电导性能

Electrical Behavious of Doped BaCeO_3 and SrCeO_3 in Oxygen,Hydrogen and Water Vapor Atmospheres

掺杂碱土金属铈酸盐系统：ＭＣｅ１－ｘＲｘＯ３－ｘ／２（Ｍ＝Ｂａ，Ｓｒ；Ｒ＝Ｙｂ，Ｙ，Ｇｄ，Ｌａ；ｘ＝０．０１～０．１０）可由固相反应制得单相化合物，Ｘ射线衍射分析表明，掺杂元素及掺杂量对掺杂ＢａＣｅＯ３和ＳｒＣｅＯ３的晶体结构影响不大．用复数阻抗谱研究了在氧、氢、水气气氛下的电导性能．在各种气氛下ＭＣｅ０．９５Ｙｂ０．０５Ｏ２．９７５（Ｍ＝Ｂａ，Ｓｒ）的电导率最大．根据测试结果，结合缺陷化学理论讨论了在各种气氛下的导电机理．在氧气气氛下，掺杂ＢａＣｅＯ３和ＳｒＣｅＯ３是氧离子和电子的混合导体，而在氢及水气气氛下是质子导体．

Single phase compounds of doped cerate perovskite: MCe1-xRxO3-x/2 (M=Ba, Sr; R=Yb, Y,Gd, La; x=0.01～0.10) have been prepared by solid reaction. The X-ray study shows that the doping elements and quantity have little influence on the crystal structures of doped BaCeO3 and SrCeO3. The conductivity of doped cerate perovskite has been studied in atmospheres of oxygen, hydrogen and water Vapor at temperatures ranging from 200 ℃ to 1000 ℃ using impedance spectroscopy. Under these three atmospheres the highest conductivities were observed for the composition of MCe0.95Yb0.05O2.975 (M=Ba,Sr). The transport processes in the solids have been discussed with the results and defect chemistry. In oxygen the doped BaCeO3 and SrCeO3 are the oxygen ion and electron mixed conductors while in hydrogen and water mper atmospheres they are proton conductors.