コロイドナノ結晶から作られた,CO2+ドーピングされたTiO2で,強い室温フェロマグネティズム
J Daniel Bryan1, Steve M Heald, Scott A Chambers
1Contribution from the Department of Chemistry, University of Washington, Seattle, WA 98195-1700, USA.
Journal of the American Chemical Society
|September 16, 2004
まとめ
コバルト・ドーピングされた二酸化チタン (TiO2) ナノ結晶は,調節可能な鉄磁気性を示す. この研究は,スピントロニックデバイスの構成要素としての潜在能力を強調しています.
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
- ナノテクノロジー ナノテクノロジー
背景:
- 稀薄磁性半導体 (DMS) は,スピントロニクスにとって有望である.
- 二酸化チタン (TiO2) は,広く研究されている半導体材料です.
研究 の 目的:
- コバルトドーピングされたコロイド性TiO2 (アナタゼ) ナノ結晶を合成し,特徴づけること.
- これらのナノ結晶の磁性特性を異なる状態 (孤立,集積,フィルム) で調査する.
- スピントロニクスアプリケーションの潜在能力を探求する.
主な方法:
- コバルトを添加したコロイド性TiO2ナノ結晶の合成.
- 電子吸収,磁気循環二重化,伝送電子顕微鏡,磁気感受性,X線吸収光譜 (XAS) を用いた特徴付け.
- 単離,集積,薄膜状態における磁気特性の評価.
主要な成果:
- コバルトドーパントは,Co2+) 酸化状態に存在する.
- 孤立したナノ結晶におけるパラマグネティズム,集積されたときの弱いフェロマグネティズム.
- スピンコーティングされたナノ結晶フィルム (最大1.9マイクロB/Co2+)) で観察された強い鉄磁気性.
結論:
- 実験的証拠は,コバルトで添加されたTiO2.2の固有の鉄磁性を支持しています.
- コロイド性TiO2 DMSナノ結晶は,鉄磁性ナノ構造に組み立てることができます.
- これらの材料は,将来のスピントロニクスアプリケーションの可能性を秘めています.
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