High-temperature creep resistance in lanthanoid ion-doped polycrystalline Al2O3

H. Yoshida, Y. Ikuhara, T. Sakuma

    Research output: Contribution to journalArticlepeer-review

    55 Citations (Scopus)

    Abstract

    High-temperature creep resistance in polycrystalline Al2O3with 0.05mol% lanthanoid oxides of Y, Sm, Eu, Tm or Lu has been examined by uniaxial compression creep testing at 1250°C. The creep resistance is improved by the doping, and the dopant effect is dependent on the type of lanthanoid; the effect is in the order Sm<Tm<Eu<Y<Lu. Each dopant cation was found to segregate in grain boundaries and is likely to suppress grain-boundary diffusion. The change in chemical bonding state with doping was estimated by a first-principles molecular orbital calculation using the discrete variational (DV)- Xαmethod. A good correlation is found between the creep resistance and the net charge of the constituent ions. A change in the ionic bonding state in grain boundaries due to lanthanoid segregation must be the origin of the improved creep resistance in polycrystalline Al2O3.

    Original languageEnglish
    Pages (from-to)249-256
    Number of pages8
    JournalPhilosophical Magazine Letters
    Volume79
    Issue number5
    DOIs
    Publication statusPublished - 1999 May

    ASJC Scopus subject areas

    • Condensed Matter Physics

    Fingerprint Dive into the research topics of 'High-temperature creep resistance in lanthanoid ion-doped polycrystalline Al<sub>2</sub>O<sub>3</sub>'. Together they form a unique fingerprint.

    Cite this