まとめ
高圧により,シリコン (Si) はシリケート液体へと変化し,その局所的幾何学が変化します. この研究では, (29) Si NMRを用いてSi調整の圧力誘発変化を検知し,無形相における八面体Siへのシフトを明らかにした.
科学分野:
- 地質化学 地質化学
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
背景:
- シリケート液体中のシリコン (Si) カチオンの調整と局所幾何学は,マグマの特性にとって極めて重要です.
- 圧力下でのこれらの構造変化を理解することは,地化学と材料科学にとって不可欠です.
研究 の 目的:
- シリケートガラスのSi調整の圧力誘発変化を調査する.
- 高圧下における無形相におけるSiの局所原子構造を特徴づけるために.
主な方法:
- (29) Si マジックアングル回転核磁共振 (MAS NMR) スペクトロメトリーを使用しました.
- 高圧 (8 GPa) と高温 (1500 °C) で消し去られたガラスのサンプルを分析したナトリウムジシケート (Na(2) Si(2) O(5)).
主要な成果:
- 8 GPaと1500 °Cで消し去られたガラスに約1.5%のオクターエドールSiの存在が検出されました.
- 八面体Siが均質で無形な相の一部であることを確認しました.
- 圧力の増加に伴い,ブリッジングとノンブリッジングの酸素のよりランダムな分布に向けて,支配的な四面体Si種化の不均衡が観察されました.
結論:
- 高圧は,シリケートガラスにおけるSi調整の移行を誘導する.
- 観測された構造の変化は,シイケーションの周りの酸素種の分布に影響を与えます.
- これらの発見は,極端な条件下でシリケート液体の振る舞いについての洞察を提供します.
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