Oxygen Partial Pressure Dependence of In Situ X-Ray Absorption Spectroscopy at Co and Fe K-Edge for (La0.6Sr0.4)(Co0.2Fe0.8)O3-δ

被引：2
作者：
Itoh, Takanori [1 ]
Shirasaki, Saori [1 ]
Ofuchi, Hironori [2 ]
Hirayama, Sayaka [2 ]
Honma, Tetsuo [2 ]
Mori, Masashi [3 ]
Nakayama, Masanobu [4 ]
机构：
[1] AGC Seimi Chem Co Ltd, Chigasaki, Kanagawa 2538585, Japan
[2] Japan Synchrotron Radiat Res Inst JASRI, SPring 8, Sayo, Hyogo 6795198, Japan
[3] Cent Res Inst Elect Power Ind, Yokosuka, Kanagawa 2400196, Japan
[4] Nagoya Inst Technol, Dept Mat Sci & Engn, Showa Ku, Nagoya, Aichi 4668555, Japan
来源：
JOURNAL OF FUEL CELL SCIENCE AND TECHNOLOGY | 2012年 / 9卷 / 03期
关键词：
X-ray absorption spectroscopy; X-ray absorption near-edge structure; perovskite oxide; solid state fuel cell; electrode materials; crystal structure; ionic conduction; CHEMICAL DIFFUSION; 3-DIMENSIONAL VISUALIZATION; CRYSTAL-STRUCTURE; CHARGE-DENSITY; NONSTOICHIOMETRY; CONDUCTIVITY; OXIDES; LA0.6SR0.4CO0.8FE0.2O3-DELTA; PEROVSKITES;
D O I：
10.1115/1.4005608
中图分类号：
O646 [电化学、电解、磁化学];
学科分类号：
081704 ;
摘要：
(La0.6Sr0.4)(Co0.2Fe0.8)O3-delta (LSCF) has been promised as a cathode material of solid oxide fuel cells at intermediate temperatures. Despite the many previous studies of LSCF that have been reported, the role of Co and Fe atoms in the oxygen ion conduction is still unclear. In this work, we aimed at presenting each valence, oxygen chemical diffusion coefficient (D-chem) and activation energy (E-a) related to Co and Fe in LSCF by in situ X-ray absorption spectroscopy (XAS) at high temperatures and during reduction. For quantitative analysis of X-ray absorption near edge structure (XANES) spectroscopy, these results indicated that the Co valence decreased more easily than the Fe valence. On the other hand, from relaxation plots of the Co and Fe valence during reduction, the values of D-chem and E-a related to Co and Fe were nearly equal. Considering equations showing the oxygen ion conductivity, these results would indicate that oxygen ion conductivity was contributed by Co with more oxygen vacancies rather than Fe. According to these results, a structural model with and without oxygen vacancies and the oxygen ion conduction mechanism of LSCF was speculated, that is, we found that oxygen ion conductivity was more closely related to Co than Fe in LSCF by direct observations of in situ XAS. [DOI:10.1115/1.4005608]
引用
收藏
页数：8
相关论文
共 34 条
  • [1] Chemical diffusion in perovskite cathodes of solid oxide fuel cells:: the Sr doped LaMn1-xMxO3 (M=Co, Fe) systems
    Badwal, SPS
    Jiang, SP
    Love, J
    Nowotny, J
    Rekas, M
    Vance, ER
    [J]. CERAMICS INTERNATIONAL, 2001, 27 (04) : 419 - 429
  • [2] Observation of the compensation law during oxygen diffusion in perovskite materials
    Berenov, AV
    MacManus-Driscoll, JL
    Kilner, JA
    [J]. INTERNATIONAL JOURNAL OF INORGANIC MATERIALS, 2001, 3 (08): : 1109 - 1111
  • [3] Defect equilibria and partial molar properties of (La,Sr)(Co,Fe)O3-δ
    Bucher, E.
    Sitte, W.
    Caraman, G. B.
    Cherepanov, V. A.
    Aksenova, T. V.
    Ananyev, M. V.
    [J]. SOLID STATE IONICS, 2006, 177 (35-36) : 3109 - 3115
  • [4] OXYGEN-TRANSPORT IN SELECTED NONSTOICHIOMETRIC PEROVSKITE-STRUCTURE OXIDES
    CARTER, S
    SELCUK, A
    CHATER, RJ
    KAJDA, J
    KILNER, JA
    STEELE, BCH
    [J]. SOLID STATE IONICS, 1992, 53 : 597 - 605
  • [5] MIXED ELECTRONIC/IONIC CONDUCTIVITY OF THE SOLID-SOLUTION LA(1-X)SRXCO(1-Y)NIYO3-DELTA (X= 0.4, 0.5, 0.6 AND Y= 0.2, 0.4, 0.6)
    FTIKOS, C
    CARTER, S
    STEELE, BCH
    [J]. JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 1993, 12 (01) : 79 - 86
  • [6] A NEW CLASS OF OXYGEN SELECTIVE CHEMICALLY DRIVEN NONPOROUS CERAMIC MEMBRANES .1. A-SITE DOPED PEROVSKITES
    GUR, TM
    BELZNER, A
    HUGGINS, RA
    [J]. JOURNAL OF MEMBRANE SCIENCE, 1992, 75 (1-2) : 151 - 162
  • [7] Oxygen nonstoichiometry and thermo-chemical stability of La0.6Sr0.4Co1-yFeyO3-δ (y=0.2, 0.4, 0.6, 0.8)
    Hashimoto, Shin-ichi
    Fukuda, Yasuhiro
    Kuhn, Melanie
    Sato, Kazuhisa
    Yashiro, Keiji
    Mizusaki, Junichiro
    [J]. SOLID STATE IONICS, 2010, 181 (37-38) : 1713 - 1719
  • [8] Study of oxygen ion diffusion in (Ba0.5Sr0.5)(Co0.8Fe0.2)O2.33-δ through in-situ neutron diffractions at 300 and 720 K
    Itoh, Takanori
    Hirai, Takene
    Yamashita, Junichi
    Watanabe, Syouji
    Kawata, Etsuya
    Kitamura, Naoto
    Idemoto, Yasushi
    Igawa, Naoki
    [J]. PHYSICA B-CONDENSED MATTER, 2010, 405 (08) : 2091 - 2096
  • [9] Study of charge density and crystal structure of (La0.75Sr0.25)MnO3.00 and (Ba0.5Sr0.5)(Co0.8Fe0.2)O2.33-δ at 500-900 K by in situ synchrotron X-ray diffraction
    Itoh, Takanori
    Shirasaki, Saori
    Fujie, Yoshinori
    Kitamura, Naoto
    Idemoto, Yasushi
    Osaka, Keiichi
    Ofuchi, Hironori
    Hirayama, Sayaka
    Honma, Tetsuo
    Hirosawa, Ichiro
    [J]. JOURNAL OF ALLOYS AND COMPOUNDS, 2010, 491 (1-2) : 527 - 535
  • [10] Determination of the crystal structure and charge density of (Ba0.5Sr0.5)(Co0.8Fe0.2)O2.33 by Rietveld refinement and maximum entropy method analysis
    Itoh, Takanori
    Nishida, Yuuki
    Tomita, Aya
    Fujie, Yoshinori
    Kitamura, Naoto
    Idemoto, Yasushi
    Osaka, Keiichi
    Hirosawa, Ichiro
    Igawa, Naoki
    [J]. SOLID STATE COMMUNICATIONS, 2009, 149 (1-2) : 41 - 44
1234