地球の中心にある体中心の立方体鉄の熱的・化学的安定化の可能性
Lidunka Vocadlo1, Dario Alfè, M J Gillan
1Research School of Earth Sciences, Birkbeck College and University College London, UK. l.vocadlo@ucl.ac.uk
Nature
|August 2, 2003
まとめ
地球の内核は,体中心の立方体 (b.c.c.) を含んでいるかもしれない. 鉄の合金,純粋な鉄ではない. 硫黄やシリコンのような不純物は,この相を安定させ,潜在的に内核の複雑性の地震観測を説明します.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- マテリアルサイエンス 材料科学
- 量子力学は,量子力学という
背景:
- 地球の固体の中核における鉄の安定相については,依然として議論が続いている.
- 地震学的データは,複雑な内核層構造を示唆している.
- 以前の理論は,六角密集型 (h.c.p.) を好んでいた. 鉄はコアの圧力で,鉄はコアの圧力で,鉄はコアの圧力で.
研究 の 目的:
- 体中心の立方体 (b.c.c.) の安定性を調査する. 鉄は,地球の内核の条件で存在している.
- 鉄の結晶構造に及ぼす温度と不純物の影響を判断する.
- 理論的な予測と地震学的観測を調和させる.
主な方法:
- アブ・イニシオ分子動力学を用いた量子力学の研究.
- 核の圧力と温度での振る舞いをモデル化するための自由エネルギー計算.
- b.c.c.c.の分析について そしてh.c.p. 鉄相は,不純物を含んでいるか,含まないかです.
主要な成果:
- 身体中心の立方体 (b.c.c.) 鉄は核の温度でエントロピー的に安定する.
- 純粋なh.c.p.である. 鉄は熱力学的に安定しています.
- 硫黄やシリコンの汚れはBCCを安定させる. h.c.p.をフェーズオーバーする. ステージ. ステージ. ステージ.
結論:
- 純粋な鉄ではなく,BCC構造の鉄合金は,地球の内核の強い候補である.
- 不純物はBCCの安定化に重要な役割を果たします. ステージ. ステージ. ステージ.
- この発見は,内核の観測された地震的複雑さの潜在的な説明を提供します.
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