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マグネタイト3Dのコロイド結晶は,46億年前に初期の太陽系で形成されました
Jun Nozawa1, Katsuo Tsukamoto, Willem van Enckevort
1Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Sendai 980-8578, Japan.
Journal of the American Chemical Society
|May 14, 2011
まとめ
磁石ナノ結晶の古代のコロイド結晶は,隕石で発見された. 独特の粒子の形態学と磁場構造により形成が可能になり,鉄磁性材料の以前の合成原理に異議を唱えました.
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
- ナノテクノロジー ナノテクノロジー
背景:
- 三次元コロイド結晶は,強い磁気相互作用のために,鉄磁気粒子を使用して合成することが通常困難です.
- マグネタイト (Fe(3) O(4) は,一般的な鉄磁気材料である.
- オパールのような天然のコロイド結晶は,太陽系の年齢よりもかなり若い.
研究 の 目的:
- タギシュ湖の隕石で発見された古代のコロイド結晶の形成と構造を調査するために.
- フェロ磁性ナノ結晶の自己組み立てにおける粒子形態学と磁性特性の役割を理解する.
主な方法:
- コロイド結晶を含む隕石のサンプルを分析する.
- マグネタイトナノクリスタライトの大きさ,形状,および包装構造の特徴.
- 観測された結晶形成に基づいた磁域構造を仮説化する.
主要な成果:
- タギシュ湖の隕石の中に,均等サイズ (数百ナノメートル) の磁石ナノクリスタライトで構成される3Dのコロイド結晶を発見した.
- これらの結晶は,約46億年前のもので,地上の天然のコロイド結晶よりも古い.
- マグネタイトの粒子の大きさは個々の形態を決定し,コロイド結晶の全体的な構造に影響を与えます.
結論:
- これらの古代の鉄磁性コロイド結晶の形成は,強力な磁気相互作用がそれらの合成を防ぐという原理に挑戦しています.
- 各磁石粒子の磁気領域構造は,磁石粒子の間の磁気力を軽減し,自己組み立てを可能にします.
- この発見は,初期の太陽系条件下で磁性ナノマテリアルの自己組織化についての洞察を提供します.
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