H2O氷の高圧相のインシトゥー観測
1I. Chou, 955 National Center, U.S. Geological Survey, Reston, VA 20192, USA. J. G. Blank, A. F. Goncharov, H. Mao, R. J. Hemley, Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad.
まとめ
科学者たちは,水 (H2O) の新しい固体相を発見し,独特の結晶構造と融解行動を持っています. この発見は,水についての私たちの理解を広げています.
科学分野:
- 固体化学 固体化学
- マテリアルサイエンス 材料科学
- 地質物理学 地質物理学とは地質物理学です.
背景:
- 水 (H2O) は,様々な圧力-温度条件下で,多数の固体相 (氷) で存在します.
- これらの相を理解することは,惑星科学と高圧物理学にとって極めて重要です.
- 以前の研究で多くの氷の多形体が特定されましたが,完全な相図は不完全のままです.
研究 の 目的:
- 水のこれまで未知の固体相を特定し,特徴づけること.
- 圧力-温度溶融関係とこれらの相の構造的性質を調査する.
主な方法:
- 氷結晶の成長と融解の直接観察は,水熱ダイアモンド・アンビル・セルを用いて行われました.
- 1203kg/m3から1257kg/m3までのH2Oの散発密度の分析
- -10°Cから50°Cまでの温度で実施された測定.
- 振動ラーマン光譜を用いた特徴化.
主要な成果:
- H2Oの新型,これまで未知の固体相の特定.
- 新しい段階では,明確な成長パターンと圧力-温度融解関係が観察されました.
- 新氷期は,無秩序なアニソトロピック構造を示し,氷VIと類似性を示しています.
- 4つの氷の形態 (氷V,VI,IV,および新段階) が実験条件下で溶けることが観察されました.
結論:
- 水の新しい固体相が実験的に確認されました.
- 新しいフェーズは,ユニークな構造と熱力学特性を有しています.
- この発見は,H2O相図のより包括的な理解に貢献しています.
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