Conductivity, transport number measurements and hydration thermodynamics of BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ)

Sandrine Ricote, Nikolaos Bonanos, Hsiang-Jen Wang, R. Haugsrud

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ) compounds with ξ = 0.01 and 0.02 have been synthesized by solid state reaction at 1400 °C and sintered at 1450 °C. TEM analyses were performed and showed a segregation of nickel at the grain boundaries for ξ = 0.02. This apparent solubility limit of Ni in the B-site of the perovskite is in agreement with similar data obtained earlier for the two compositions. The first aim of this work was to evaluate the conductivity of BaCe0.2Zr0.7Y(0.1 − ξ)NiξO(3 − δ) at temperature between 500 and 900 °C, using impedance spectroscopy at different oxygen partial pressures and water vapor pressures, as well as the emf technique. The compounds exhibit p-type conduction in oxidizing atmosphere, and ionic conduction elsewhere. The oxide ion contribution of the conductivity is negligible only for temperatures below 600 °C. The determination of hydration enthalpies, our second goal, was achieved by modelling of the conductivity data and by thermogravimetric measurements (TG-DSC).
    Original languageEnglish
    JournalSolid State Ionics
    Volume185
    Issue number1
    Pages (from-to)11-17
    ISSN0167-2738
    DOIs
    Publication statusPublished - 2011

    Keywords

    • Membranes

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