金属ガラスの長距離トポロジカル・オーダー
Qiaoshi Zeng1, Hongwei Sheng, Yang Ding
1International Center for New-Structured Materials, Zhejiang University, Hangzhou 310027, People's Republic of China.
Science (New York, N.Y.)
|June 18, 2011
まとめ
金属ガラスの展示は,隠された長距離注文を隠しています. 高圧下では,Ce75) Al25) メタリックガラスは単一結晶に変形し,その基礎となるトポロジック構造を明らかにします.
科学分野:
- 材料科学 材料科学とは
- 凝縮物質物理学 凝縮物質物理学
- クリスタログラフィーです.
背景:
- 水晶は,金属ガラスなどの無形物質とは異なり,長距離周期的原子秩序を持っています.
- Ce ((75) Al ((25)) メタリックガラスは,以前は構造的に無形で同otropicと考えられていた.
研究 の 目的:
- 金属ガラスのCe(75) Al(25) の内にある隠された構造的秩序を調査する.
- この金属ガラスの圧力誘発結晶化のメカニズムを理解するために.
主な方法:
- 高圧実験では,25ギガパスカルまでの水静圧を用いた高圧実験を行った.
- 構造分析のためのシンクロトロンX線 difraktion技術.
- 原子の振る舞いをモデル化するための分子動力学シミュレーション.
主要な成果:
- Ce ((75) Al ((25)) メタリックガラスは,無形に見えるにもかかわらず,長距離のトポロジカル・オーダーを持っています.
- 高圧下では,金属ガラスは,均一な方向性を有する,片面中心の立方体 (fcc) 結晶に変形します.
- Ce と Al の間の原子サイズの不一致は結晶化を妨げますが,トポロジカルな順序は維持されます.
結論:
- 遠距離 fcc トポロジカル・オーダーは,原子不一致によってマスクされたCe(75) Al(25) メタリック・グラスに存在する.
- セリウムの圧力誘発の電子移行は原子不一致を排除し,トポロジカル・オーダーが単一結晶として顕現することを可能にします.
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