Oxygen nonstoichiometry and chemical expansion of mixed conducting La0.1Sr0.9Co0.8Fe0.2O3-δ

被引：21
作者：
Choi, M. -B. [1 ]
Lim, D. -K. [1 ]
Wachsman, E. D. [2 ]
Song, S. -J. [1 ]
机构：
[1] Chonnam Natl Univ, Dept Mat Sci & Engn, Kwangju 500757, South Korea
[2] Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA
来源：
SOLID STATE IONICS | 2012年 / 221卷
基金：
新加坡国家研究基金会;
关键词：
Perovskite; Ionic conductivity; Nonstoichiometry; ELECTRICAL-TRANSPORT PROPERTIES; DEFECT CHEMISTRY; PERMEATION; DIFFUSION; LA1-XSRXCO1-YFEYO3; COEFFICIENT; RELAXATION; MEMBRANE; EXCHANGE;
D O I：
10.1016/j.ssi.2012.06.012
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
The chemical diffusivity and surface exchange constant of La0.1Sr0.9Co0.8Fe0.2O3-delta (LSCF1982) were successfully extracted by using the chemical expansion relaxation method, and the oxygen nonstoichiometry was determined by electrochemical coulometric titration as a function of oxygen partial pressure (pO(2)) and temperature. The oxygen chemical diffusivity and surface exchange constants were 3.16 x 10(-4) cm(2)/s and 6.31 x 10(-3) cm/s at 1000 degrees C in air, respectively. These values and the activation energies for oxygen diffusion were in good agreement with our own previously reported values determined from the 4-probe D.C. conductivity relaxation method. The oxygen nonstoichiometry was increased with decreasing pO(2) and increasing temperature, due to the thermal and chemical release of lattice-site oxygen from the lattice sites. The oxygen self-diffusion coefficient and ionic conductivity were successfully extracted from the relation between the oxygen nonstoichiometry and the chemical diffusion coefficient, and are best expressed by the following equations: D-0/cm(2)/s = (1.75 +/- 0.05) x 10(-4) exp (-0.68 +/- 0.10eV/kT)vertical bar(pO2-0.21 atm) sigma T-ion/cm(2)/sK(-1) = (4.01 +/- 0.02) x 10(5) exp (-0.65 +/- 0.04eV/kT)vertical bar(pO2=0.21 atm) (C) 2012 Elsevier B.V. All rights reserved.
引用
收藏
页码：22 / 27
页数：6
相关论文
共 37 条
[1]  
Adler SB, 2001, J AM CERAM SOC, V84, P2117, DOI 10.1111/j.1151-2916.2001.tb00968.x
[2]  
Benson S.J., 1997, P 3 INT S MIX ION CO, V97-24
[3]   Defect equilibria and chemical expansion in non-stoichiometric undoped and gadolinium-doped cerium oxide [J].
Bishop, S. R. ;
Duncan, K. L. ;
Wachsman, E. D. .
ELECTROCHIMICA ACTA, 2009, 54 (05) :1436-1443
[4]   Oxygen nonstoichiometry and exchange kinetics of Ba0.5Sr0.5Co0.8Fe0.2O3-δ [J].
Bucher, Edith ;
Egger, Andreas ;
Ried, Peter ;
Sitte, Werner ;
Holtappels, Peter .
SOLID STATE IONICS, 2008, 179 (21-26) :1032-1035
[5]  
Chen X., 2007, THESIS U WASHINGTON
[6]   Thermal and chemical expansion of Sr-doped lanthanum cobalt oxide (La1-xSrxCoO3-δ) [J].
Chen, XY ;
Yu, JS ;
Adler, SB .
CHEMISTRY OF MATERIALS, 2005, 17 (17) :4537-4546
[7]   Thermodynamic quantities and oxygen nonstoichiometry of undoped BaTiO3-δ by thermogravimetric analysis [J].
Choi, M. -B. ;
Jeon, S. -Y. ;
Im, H. -N. ;
Song, S. -J. .
JOURNAL OF ALLOYS AND COMPOUNDS, 2012, 513 :487-494
[8]   Determination of Oxygen Chemical Diffusivity from Chemical Expansion Relaxation for BaCo0.7Fe0.22Nb0.08O3-δ [J].
Choi, M. -B. ;
Jeon, S. -Y. ;
Yang, H. -S. ;
Park, J. -Y. ;
Song, S. -J. .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2011, 158 (02) :B189-B193
[9]   High-temperature transport properties of La0.1Sr0.9Co0.8Fe0.2O3-δ [J].
Choi, M-B. ;
Jeon, S-Y. ;
Park, J-Y ;
Yang, H-S. ;
Song, S-J. .
SOLID STATE IONICS, 2011, 192 (01) :269-274
[10]   Defect chemistry and oxygen transport of (La0.6Sr0.4-xMx)0.99Co0.2Fe0.8O3-δ, M = Ca (x=0.05, 0.1), Ba (x=0.1, 0.2), Sr Part I: Defect chemistry [J].
Dalslet, Bjarke Thomas ;
Sogaard, Martin ;
Bouwmeester, Henny J. M. ;
Hendriksen, Peter Vang .
SOLID STATE IONICS, 2009, 180 (20-22) :1173-1182
1234