Measurement of electrical conductivity of La0.2Sr0.8Cr0.2Fe0.8O3-δ using gas-tight electrochemical cells

被引:6
作者
Yoo, Jiho [1 ]
Kim, Sangdo [1 ]
Choi, Hokyung [1 ]
Rhim, Youngjoon [1 ]
Lim, Jeonghwan [1 ]
Lee, Sihyun [1 ]
Jacobson, Allan J. [2 ]
机构
[1] Korea Inst Energy Res, Climate Change Technol Div, Taejon 305343, South Korea
[2] Univ Houston, Dept Chem, Houston, TX 77004 USA
关键词
La0.2Sr0.8Cr0.2Fe0.8O3-delta; Perovskite; Electrical conductivity; SOFC; PEROVSKITE-TYPE OXIDES; OXYGEN NONSTOICHIOMETRY; DEFECT STRUCTURE; TRANSPORT; LA1-XSRXFEO3-DELTA; EQUILIBRIUM; COEFFICIENT; TEMPERATURE; MODEL;
D O I
10.1007/s10832-010-9627-2
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
The oxygen partial pressure (pO(2)) dependence of the electrical conductivity of La0.2Sr0.8Cr0.2Fe0.8O3-delta (LSCrF) was obtained at T = 750-1060A degrees C and pO(2) = 10(-18)-0.5 atm. The slope of the plot of log sigma vs. log pO(2) is similar to 1/5 in the p-type region, pO(2) = 10(-5)-10(-1) atm. The p-n transition pO(2) increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 942A degrees C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite.
引用
收藏
页码:56 / 62
页数:7
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