地球の中心にある体中心の立方体鉄・ニッケル合金
L Dubrovinsky1, N Dubrovinskaia, O Narygina
1Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.
まとめ
地球の核には,鉄-ニッケル合金が含まれている可能性が高い. 高圧,高温の実験では,この合金が体中心の立方体構造を採用し,地球の深い内部のモデルをサポートしていることが示されています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 高圧鉱物物理 高圧鉱物物理
- 宇宙化学 (コスモケミストリー)
背景:
- 地化学的および地物理学的証拠は,地球の核は,重要なニッケル含有量 (5-15%) の鉄で構成されていることを示唆しています.
- 核条件における鉄・ニッケル合金の構造と振る舞いを理解することは,惑星の内部をモデル化するために極めて重要です.
研究 の 目的:
- 鉄・ニッケル合金 (Fe{0.9}Ni{0.1}) の in situ 構造と性質を極度の圧力と温度下で調査する.
- 地球の核の組成に関連する鉄-ニッケル合金の相態を決定する.
主な方法:
- 内部で加熱されたダイヤモンドアンビルセル (DAC) を使用したインシット角分散型X線 difrraction.
- 圧力と温度による電気抵抗の測定.
- シミュレートされたコア条件下での合金行動の実験的および理論的分析.
主要な成果:
- 鉄・ニッケル合金Fe ((0.9) Ni ((0.1) は,225 GPaを超える圧力と3400 Kを超える温度で体中心の立方体 (bcc) 構造を採用することが観察されました.
- 実験結果は,理論的予測と一致し,純粋鉄の衝撃波データ解釈を支持し,約200GPaの固体-固体相転換を示しています.
結論:
- この研究は,地化学的に妥当な組成物 (ニッケル,硫黄,シリコンを含む) の鉄合金が,地球の内核で観察される体中心の立方体構造を形成する可能性が高いという仮説を支持する.
- これらの発見は,核の組成と構造に関する私たちの理解を洗練し,惑星の形成と進化のモデルに貢献しています.
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