Defect doping and characterization in oxide single crystals using femtosecond laser

Shingo Kanehira, Chiwon Moon, Eita Tochigi, Naoya Shibata, Yuichi Ikuhara, Kiyotaka Miura, Kazuyuki Hirao

    Research output: Chapter in Book/Report/Conference proceedingConference contribution


    Defects inside oxide ceramics of magnesium oxide (MgO) and sapphire (Al2O3) were formed using femtosecond laser irradiation. The laser irradiance in these ceramics forms various defects classified as dislocations, twins, or nano cracks near the focal point due to the increase of temperature and successive generation of Shockwave within several picoseconds. The morphology of defects mainly depends on the crystal structure; dense dislocations inside MgO with a rock-salt type structure, and nanocracks, dislocations, or twins in sapphire with a corundum structure. The TEM analysis revealed that the dense dislocations formed on the two slip planes {110} to form a cross-shaped pattern when the laser beam focused on the (100) plane in MgO. In case of sapphire crystal, cracks propagated from the focal point that has an amorphous structure along R-planes {11-02}, which had the lowest fracture surface energy. The nano crack transformed into the aligned void and dislocation structure during the heat treatment over 1573K, which is one of the crack healing effect.

    Original languageEnglish
    Title of host publicationAdvanced Materials for Applications in Extreme Environments
    Number of pages6
    Publication statusPublished - 2011
    Event2010 MRS Fall Meeting - Boston, MA, United States
    Duration: 2010 Nov 292010 Dec 3

    Publication series

    NameMaterials Research Society Symposium Proceedings
    ISSN (Print)0272-9172


    Other2010 MRS Fall Meeting
    Country/TerritoryUnited States
    CityBoston, MA

    ASJC Scopus subject areas

    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering


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