六角形のテンプレート上の氷の成長中のストレスの軽減

Nikki Gerrard¹, Chiara Gattinoni², Fiona McBride¹

¹Surface Science Research Centre and Department of Chemistry , University of Liverpool , Liverpool L69 3BX , United Kingdom.

Journal of the American Chemical Society

|April 27, 2019

まとめ

研究者達は水の分子が表面に氷を形成する方法を発見しました 2層目の水は欠陥列を使ってストレスを管理し表面の違いにもかかわらず氷の成長を可能にします

科学分野:

異質な氷の核化
表面科学
材料科学

背景:

表面での氷核形成の顕微鏡のメカニズムは不明である.
表面のテンプレートは水の構造に影響し,最初の氷層にストレスを引き起こします.
初期の氷の成長におけるストレスの適応を理解することは極めて重要です

研究の目的:

格子不一致のPt合金表面での初期氷の成長段階を調査する.
薄い氷の膜に水がどのように収納されるかを明確にします.
氷の核形成と成長の分子規模のメカニズムを特定する.

主な方法:

スキャントンネル顕微鏡 (STM)
低エネルギー電子散射 (LEED)
作業機能の測定
電子構造の計算

主要な成果:

最初の水層は,Pt合金表面に比例する六角形のネットワークを形成します.
第二の水層は,2次元構造を構成し,欠陥列 (ペンタマーとオクタマーリング) が伸びている.
これらの欠陥列はストレスを軽減し,水密度を高めながらも第2層は大きく相応しい状態を保つことができます.

結論:

オクタマー・ペンタマー・デフェクト・モチーフは,薄い氷の薄膜における柔軟なストレスを軽減するメカニズムである.
このメカニズムは,他のストレートフィルムシステムとは異なり,格子不一致の表面での氷の成長を促進します.
発見は異質な氷の核形成と成長に関する分子レベルの洞察を提供します.

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