摘要
用溶胶-凝胶法制备了(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ(x=0.05,0.07,0.10)混合导体材料,用X射线衍射(XRD)分析该材料的物相,用交流阻抗法和电子阻塞电极法分别测定材料的总电导率与离子电导率,研究了A位缺位对(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ混合导体材料的结构、电性能及阻抗行为的影响。结果表明,所有试样都具有单一立方相钙钛矿结构;在测试温度范围内(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ(x=0.05,0.07,0.10)的总电导率随着温度的升高先增大后减小,表现为小极化子导电机理;随着A位缺位量的增加,总电导率降低。(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ(x=0.05,0.07,0.10)在800℃的总电导率为0.011-0.26 S·cm-1。(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ的总电导率阻抗谱只显示了高频斜线部分,说明材料主要以电子电导为主;离子传导的弛豫时间逐渐随着A位缺位量的增加而增大,说明A位缺位不利于离子在晶界中的传导。
A single phase A-site-deficient perovskite(Y0.08Sr0.92)1- xTi0.6Fe0.4O3- δ(x=0.05, 0.07, 0.10) was synthesized at 1350 oC in air by sol-gel method. The effect of A-site deficiency in(Y0.08Sr0.92)1- xTi0.6Fe0.4O3- δon its phase structure, electrical and ionic conductivity and impedance was investigated. The partial oxygen ionic conductivity decreases with the increasing A-site deficiency, which may be attributed to the tendency for oxygen vacancy ordering. The n-type electronic conductivity in air increases with the increasing A-site deficiency, which may be attributed to the decrease of [Fe'Ti] and [h?] due to the possible ionization reaction of ferric iron. The total electrical conductivity of(Y0.08Sr0.92)1-xTi0.6Fe0.4O3-δ(x=0.05, 0.07, 0.10) varies from 0.11 S·cm-1to 0.26 S·cm-1at 800 oC. Only one oblique line in high frequency range for each temperature is presented, demonstrating that the electronic conductivity should mainly contribute to the total electrical conductivity. The increase of A- site deficiency is unfavorable for ion conductivity due to a subsequently rising relaxation time.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2015年第6期429-433,共5页
Chinese Journal of Materials Research
基金
国家自然科学基金51374017资助项目~~
