メタノール単水化合物における負の線形圧縮性と大規模なアニソトロピック熱膨張
A Dominic Fortes1, Emmanuelle Suard, Kevin S Knight
1Department of Earth Sciences, University College London (UCL), Gower Street, London WC1E 6BT, UK. andrew.fortes@ucl.ac.uk
Science (New York, N.Y.)
|February 12, 2011
まとめ
研究者らは,負の線形圧縮性 (NLC) と負の熱膨張性 (NTE) を示す希少な分子結晶を発見した. この珍しい材料は圧力下で膨張し,高度な材料設計の新たな可能性を提供します.
科学分野:
- マテリアルサイエンス 材料科学
- クリスタルグラフィーです.
- 凝縮物質物理学 凝縮物質物理学
背景:
- ほとんどの材料は,水立圧下で収縮する.
- 物質が圧力下で膨張する負の線形圧縮性 (NLC) は,特に結晶固体では珍しい.
- 分子結晶のNLCを理解することは,新しい材料の開発に不可欠です.
研究 の 目的:
- 単純な分子結晶における内在の負の線形圧縮性 (NLC) を発見し,特徴づけること.
- このNLC材料の負の熱膨張 (NTE) を含む熱膨張特性を調査する.
- 観察されたNLCおよびNTE行動の背後にある構造的メカニズムを解明する.
主な方法:
- ニュートロン粉の difrractionは,水晶構造と圧力と温度下での行動を分析するために採用されました.
- 詳細な結晶学分析は,メタノールと水のデュテラート1:1化合物で行われました.
主要な成果:
- この研究では,研究された分子結晶のNLCと高度なアニソトロプ的熱膨張,NLC軸に沿ったNTEを含むNLCの両方を特定し,確認しました.
- 構造分析により,ヒドロキシル水鎖とメチル群によって形成されるアピカルリンクされたロムブスが,NLC/NTEの行動に責任があることが明らかになった.
- 材料は,水立圧縮を受けたとき,特定の軸に沿って膨張を示します.
結論:
- 単純な分子結晶であるメタノールと水のデュテラ化1:1化合物は,内在的なNLCとNTEを示しています.
- ヒドロキシル-水鎖とメチル群のユニークな構造的配置は,観察されたアニゾトロピックな振る舞いを決定する.
- この発見は,機械的および熱的刺激に対する非常識な反応を持つ材料を設計するための道を開きます.
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