Phase Stability Control of Interstitial Oxide Ion Conductivity in the La1+xSr1-xGa3O7+x/2 Melilite Family.

Research output: Contribution to journalArticleScientificpeer-review


  • Chris I. Thomas
  • Xiaojun Kuang
  • Zengqiang Deng
  • Hongjun Niu
  • John B. Claridge
  • Matthew J. Rosseinsky

Research units

  • University of Liverpool


The two-dimensional polyhedral anion network melilites La1+xSr1-xGa3O7+0.5x exhibit interstitial oxide ion cond. The solid soln. is shown to extend to x = 0.64, and the variation of the cond. with x is investigated. At high temps., all of these compds. adopt the typical tetragonal melilite structure. When x > 0.6, cooling below 600° results in a reversible phase transition to an orthorhombic structure which reduces the ionic cond. Quenching expts. have shown the tetragonal structure has a higher cond. compared to the orthorhombic structure of the same compn. Short-range order effects assocd. with this transition exercise an important influence on the compn.- and temp.-dependence of the cond. [on SciFinder(R)]


Original languageEnglish
Pages (from-to)2510-2516
Number of pages7
JournalChemistry of Materials
Issue number8
Publication statusPublished - 30 Mar 2010
MoE publication typeA1 Journal article-refereed

    Research areas

  • lanthanum strontium gallate ceramic compn ionic cond

ID: 14856719