Phase relations and conductivity of Sr-zirconates and La-zirconates

F.W. Poulsen, N. Vanderpuil

    Research output: Contribution to journalJournal articleResearch

    Abstract

    The formation of the strontium zirconates SrZrO3, Sr4Zr3O10, Sr3Zr2O7 and Sr2ZrO4, and of the lanthanum zirconates La2Zr2O7 and La2-xYZr2O7 at 1450-degrees-C was investigated by x-ray powder diffraction and DTA. Three different routes of synthesis were tested. In the Sr-zirconate system, single phase orthorhombic SrZrO3 and somewhat impure, tetragonal Sr2ZrO4 were observed, whereas the formation of ordered Ruddlesden-Popper phases, SrnZrn-1O3n-2, where n = 4 and 3, could not be verified. The conductivity of La2Zr2O7 was 3.7 X 10(-6) S/cm at 750-degrees-C and 3.8 x 10(-5) S/cm at 1000-degrees-C. The conductivity of the Sr-zirconates increases with increasing Sr/Zr ratio. Samples with a nominal composition corresponding to Sr2ZrO4 have a conductivity of 7.5 x 10(-5) and 5.9 x 10(-4) S/cm at 750 and 1000-degrees-C, respectively. For all samples one observes low activation energies for ionic conduction (0.5-0.65 eV). Formation of pyrochlore structure La2-xYZr2O7 from YSZ and La2O3 at 1450-degrees-C was demonstrated.
    Original languageEnglish
    JournalSolid State Ionics
    Volume53
    Pages (from-to)777-783
    ISSN0167-2738
    Publication statusPublished - 1992

    Fingerprint Dive into the research topics of 'Phase relations and conductivity of Sr-zirconates and La-zirconates'. Together they form a unique fingerprint.

    Cite this