HAADF-STEM study of chemical ordering in Al-Pd-Sc 1/1-crystal approximant

Yeong Gi So, Masahiro Nagao, Takuro Nagai, Koji Kimoto

研究成果: Article

3 引用 (Scopus)

抄録

The atomic structure of the Al 54Pd 31Sc 15 1/1-crystal approximant to the icosahedral quasicrystal has been studied using high-angle annular dark-field (HAADF) imaging in a scanning transmission electron microscopy (STEM). HAADF imaging directly reveals that the 1/1-phase has a periodic arrangement of Tsai-type atomic clusters, which consist of three successive shells with icosahedral symmetry as well as a disordered tetrahedron at the cluster center. In the 1/1-phase, the chemical ordering of Al and Pd is observed in the glue sites between the clusters, similar to that of Al and Au in the recently discovered Al 35Au 51Yb 14 1/1-phase, indicating a common structural feature of ternary Tsai-type approximants. Moreover, the preferential introduction of structural disorder into the second dodecahedral shell is observed in the HAADF images, which causes symmetry breaking of the 1/1-phase. On the basis of a comparison with the experimental and simulated images, a preliminary model for the atomic structure of the 1/1-phase is presented.

元の言語English
ページ(範囲)7-11
ページ数5
ジャーナルJournal of Alloys and Compounds
543
DOI
出版物ステータスPublished - 2012 12 5
外部発表Yes

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Transmission electron microscopy
Crystal atomic structure
Imaging techniques
Quasicrystals
Crystals
Scanning electron microscopy
Glues

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Chemistry
  • Metals and Alloys

これを引用

HAADF-STEM study of chemical ordering in Al-Pd-Sc 1/1-crystal approximant. / So, Yeong Gi; Nagao, Masahiro; Nagai, Takuro; Kimoto, Koji.

:: Journal of Alloys and Compounds, 巻 543, 05.12.2012, p. 7-11.

研究成果: Article

So, Yeong Gi ; Nagao, Masahiro ; Nagai, Takuro ; Kimoto, Koji. / HAADF-STEM study of chemical ordering in Al-Pd-Sc 1/1-crystal approximant. :: Journal of Alloys and Compounds. 2012 ; 巻 543. pp. 7-11.
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abstract = "The atomic structure of the Al 54Pd 31Sc 15 1/1-crystal approximant to the icosahedral quasicrystal has been studied using high-angle annular dark-field (HAADF) imaging in a scanning transmission electron microscopy (STEM). HAADF imaging directly reveals that the 1/1-phase has a periodic arrangement of Tsai-type atomic clusters, which consist of three successive shells with icosahedral symmetry as well as a disordered tetrahedron at the cluster center. In the 1/1-phase, the chemical ordering of Al and Pd is observed in the glue sites between the clusters, similar to that of Al and Au in the recently discovered Al 35Au 51Yb 14 1/1-phase, indicating a common structural feature of ternary Tsai-type approximants. Moreover, the preferential introduction of structural disorder into the second dodecahedral shell is observed in the HAADF images, which causes symmetry breaking of the 1/1-phase. On the basis of a comparison with the experimental and simulated images, a preliminary model for the atomic structure of the 1/1-phase is presented.",
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AU - Kimoto, Koji

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KW - Annular dark-field imaging

KW - Crystal approximant

KW - Icosahedral quasicrystal

KW - Scanning transmission electron microscopy

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