Dependence of thermal expansion of LaNi0.6Fe0.4O3 - δ and La0.6Sr0.4Co0.2Fe0.8O3 - δ on oxygen partial pressure

Eiki Niwa, Takuya Hashimoto

研究成果: Contribution to journalArticle査読

16 被引用数 (Scopus)

抄録

The linear thermal expansion behavior of LaNi0.6Fe0.4O3 - δ and La0.6Sr0.4Co0.2Fe0.8O3 - δ, which have attracted much interest as cathode material for solid oxide fuel cell, was measured with dilatometer under various oxygen partial pressures, P(O2). Thermal expansion coefficient of LaNi0.6Fe0.4O3 - δ is independent on P(O2) and between 1.20 × 10- 5 K- 1 and 1.35 × 10- 5 K- 1 in the measurement conditions of this study. Thermal expansion coefficient of La0.6Sr0.4Co0.2Fe0.8O3 - δ is much larger than that of LaNi0.6Fe0.4O3 - δ and increases with decreasing P(O2). The difference of P(O2) dependence of thermal expansion behavior between LaNi0.6Fe0.4O3 - δ and La0.6Sr0.4Co0.2Fe0.8O3 - δ could be ascribed to the difference of the dependence of oxygen nonstoichiometry on temperature and P(O2). Due to little variation of δ by temperature at constant P(O2) in LaNi0.6Fe0.4O3 - δ, chemical expansion due to generation of δ scarcely contributes to total expansion, while chemical expansion largely contributes to total expansion of La0.6Sr0.4Co0.2Fe0.8O3 - δ especially under low P(O2) owing to larger variation of δ by temperature at constant P(O2). By comparison with thermal expansion behavior of 8 mol% yttria stabilized ZrO2, 8YSZ, under various P(O2), it was concluded that mechanical compatibility of LaNi0.6Fe0.4O3 - δ against 8YSZ was better since La0.6Sr0.4Co0.2Fe0.8O3 - δ showed not only much larger thermal expansion coefficient than 8YSZ but also large P(O2) dependence. Chemical expansion coefficients, εchem., of LNF64 and LSCF6428 were also evaluated. The εchem. of LNF64 was almost zero whereas those of LSCF6428 were order of 10- 2, showing fair agreement with so far reported εchem. of LSCF and other oxide materials frequently used for SOFC.

本文言語英語
ページ(範囲)187-194
ページ数8
ジャーナルSolid State Ionics
285
DOI
出版ステータス出版済み - 2 1 2016
外部発表はい

All Science Journal Classification (ASJC) codes

  • 化学 (全般)
  • 材料科学(全般)
  • 凝縮系物理学

フィンガープリント

「Dependence of thermal expansion of LaNi<sub>0.6</sub>Fe<sub>0.4</sub>O<sub>3 - δ</sub> and La<sub>0.6</sub>Sr<sub>0.4</sub>Co<sub>0.2</sub>Fe<sub>0.8</sub>O<sub>3 - δ</sub> on oxygen partial pressure」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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