Supplementary data for "From local structure to nanosecond recrystallization dynamics in AgInSbTe phase-change materials"

  • Toshiyuki Matsunaga (Creator)
  • Noboru Yamada (Creator)
  • Rie Kojima (Creator)
  • Shinji Kohara (Creator)
  • Masaki Takata (Creator)
  • Jaakko Akola (Creator)
  • Robert O. Jones (Creator)
  • Tetsuo Honma (Creator)
  • Eiji Ikenaga (Creator)
  • Keisuke Kobayashi (Creator)

    Dataset

    Description

    Phase-change optical memories are based on the astonishingly rapid nanosecond-scale crystallization of nanosized amorphous ‘marks’ in a polycrystalline layer. Models of crystallization exist for the commercially used phase-change alloy Ge2Sb2Te5 (GST), but not for the equally important class of Sb–Te-based alloys. We have combined X-ray diffraction, extended X-ray absorption fine structure and hard X-ray photoelectron spectroscopy experiments with density functional simulations to determine the crystalline and amorphous structures of Ag3.5In3.8Sb75.0Te17.7 (AIST) and how they differ from GST. The structure of amorphous (a-) AIST shows a range of atomic ring sizes, whereas a-GST shows mainly small rings and cavities. The local environment of Sb in both forms of AIST is a distorted 3+3 octahedron. These structures suggest a bond-interchange model, where a sequence of small displacements of Sb atoms accompanied by interchanges of short and long bonds is the origin of the rapid crystallization of a-AIST. It differs profoundly from crystallization in a-GST.
    Date made available2017
    PublisherTampere University of Technology

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