Experimental observations on the crystalline structures of YAlO<inf>3</inf> single crystal at high temperatures

Takahiro Inoue, Takaaki Morimoto, Yoshimichi Ohki

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    5 Citations (Scopus)


    To understand the effects of thermal annealing on a high-permittivity gate insulating material YAlO<inf>3</inf>, its single crystal was annealed at various high temperatures ranging from 900 to 1300 °C and was examined by various instrumental analyses such as X-ray diffraction, infrared absorption spectroscopy, laser confocal microscopy, and atomic force microscopy. As a result, it was clarified that the crystalline YAlO<inf>3</inf> takes at least three structures in a temperature range up to 1300 °C. Namely, it is perovskite below 1160 °C, at which the garnet structure starts to appear, while an unknown structure appears at 1250 °C. On the other hand, the sample surface also shows drastic changes if the temperature exceeds 1160 °C. Furthermore, many elliptical spots are induced after the annealing at 1200 or 1250 °C. Moreover, hydroxyl groups are generated at 1300 °C. It is desirable to take these structural changes into account in determining the annealing temperature of YAlO<inf>3</inf> for various industrial purposes such as the manufacture of semiconductor devices.

    Original languageEnglish
    Pages (from-to)1423-1429
    Number of pages7
    JournalApplied Physics A: Materials Science and Processing
    Issue number4
    Publication statusPublished - 2015 Jun 1

    ASJC Scopus subject areas

    • Materials Science(all)
    • Chemistry(all)

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