Energetics of cerium-zirconium substitution in the xCe0.8y 0.2O1.9-(1 -x)Zr0.8y0.2O 1.9 system

Weiqun Chen, Alexandra Navrotsky, Yue Ping Xiong, Harumi Yokokawa

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Energetics of Ce-Zr substitution in xCe0.8Y0.2O 1.9-(1 -x)Zr0.8Y0.2O1.9 (0≤x≤1) solid solutions, potential candidates for electrolytes in solid oxide fuel cells, were investigated by high temperature oxide melt drop solution calorimetry. The enthalpies of formation relative to the solid solution end-members, Ce0.8Y0.2O1.9 and Zr 0.8Y0.2O1.9 (ΔHf,ss), are slightly positive. The whole substitution range can be divided into three regimes: a zirconia-dominated region (0≤A:<0.4), where ΔH f,ss increases from 0 to 3.9 kJ/mol; a ceria-dominated region (0.6<x≤1), where ΔHf,ss remains nearly constant at 0 to 0.7 kJ/mol; and a transitional region (0.4≤x≤0.6), where ΔH f,ss decreases from 3.9 to 0.7 kJ/mol. Such a trend in ΔH f,ss strongly supports a scavenging effect of Zr4+ on oxygen vacancies, i.e. oxygen vacancies prefer the nearest neighboring sites of Zr4+ as in yttriastabilized zirconia. The formation enthalpy from binary oxides, fluorite CeO2, monoclinic ZrO2 and C-type YO1.5, (ΔHf,ox) is also slightly positive, varying analogously to ΔHf,ss.

Original languageEnglish (US)
Pages (from-to)584-589
Number of pages6
JournalJournal of the American Ceramic Society
Volume90
Issue number2
DOIs
StatePublished - Feb 2007
Externally publishedYes

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

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