氷を210ギガパスカルに圧縮する:対称的な水素結合相の赤外線証拠
Goncharov1, Struzhkin, Somayazulu
1Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, DC 20015, USA.
Science (New York, N.Y.)
|July 12, 1996
まとめ
高圧実験では,極端な圧力下での水氷 (H2O) と重水氷 (D2O) の相変化が明らかにされています. この移行は,赤外線スペクトロスコピーを用いて観測された,対称的な水素結合を持つ構造への変換を示唆しています.
科学分野:
- マテリアルサイエンス 材料科学
- 凝縮物質物理学 凝縮物質物理学
- 惑星科学 惑星科学
背景:
- 水氷 (H2O) と重水氷 (D2O) は,惑星科学における重要な構成要素である.
- 極端な圧力下での氷の段階を理解することは,惑星の内部をモデル化するために不可欠です.
研究 の 目的:
- 高圧下でのプロトン化・デュテラ化氷の相相性を研究する.
- 圧縮時に生じる構造変化をスペクトロスコピ的方法を用いて特徴づける.
主な方法:
- H2OとD2Oの圧縮は,85~300Kの温度で210GPaまで低下する.
- シンクロトロン放射を用いた赤外線反射スペクトロスコーピーは,スペクトルの変化を分析します.
- ソフトモードの行動と圧力誘発のスペクトルシフトの分析.
主要な成果:
- 60GPaのH2O氷と70GPaのD2O氷で相変化が観察されました.
- 移行は,移行圧力の下の nu3 O-H/O-D ストレッチのソフトモードの振る舞いを含み,その上に硬化が続いた.
- 顕微鏡の特徴は,対称的な水素結合を持つ構造への変換を示し,210GPaまで持続しました.
結論:
- この研究は,対称的な水素結合を持つ新しい高圧氷相の証拠を提供します.
- この発見は,太陽系の氷の体の組成と構造を理解するための意味を持つ.
- 150-160 GPaでの振動モードの結合の変化は,極端な圧力下でのさらなる構造的複雑性を示唆しています.
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