耐鉄磁性/耐鉄磁性コア/シェル MnOナノ粒子におけるサイズに依存する受動化シェルと磁性特性
Alberto López-Ortega1, Dina Tobia, Elin Winkler
1Centre d'Investigació en Nanociència i Nanotecnologia (ICN-CSIC), Campus Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.
Journal of the American Chemical Society
|June 24, 2010
まとめ
酸化マンガン (MnO) コアナノ粒子の被動化シェルの段階は,磁性特性に影響するサイズに依存します. より小さなナノ粒子は,磁性アニソトロピーの強化とネール温度を示しています.
科学分野:
- 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
- 固体物理 固体物理学
背景:
- コア/シェルナノ粒子は,異なる材料を組み合わせることで調節可能な性質を提供します.
- マンガンの酸化物 (MnO) は,相と構造に依存する多様な磁気行動を示す.
研究 の 目的:
- 双磁性核/殻ナノ粒子の磁性特性を調査する.
- ナノ粒子のサイズがシェルフェーズと磁気特性に与える影響を理解する.
主な方法:
- 核/殻ナノ粒子の合成で,MnOの核とフェルマグネティック・シェル.
- 殻相 (ガンマ-Mn(2) O(3) またはMn(3) O(4) を決定するための構造的特徴.
- ネール温度,磁性アニソトロピー,およびドメインの振る舞いを評価するための磁性特性.
主要な成果:
- シェル相組成は,ナノ粒子サイズによって変化する:ガンマ-Mn(2) O(3) は小さな粒子で優位,Mn(3) O(4) は大きい粒子で増加する.
- 核の大きさの減少とともに,MnO核のネール温度 (T(N)) と磁性アニソトロピーの有意な増加.
- 高温でMnOの持続磁気モーメントを観測し,異常な磁気領域の温度依存性.
結論:
- ナノ粒子のサイズは,MnOコア/シェルシステムの相および磁気特性を制御する重要な要因です.
- 強化されたT (N) とアニソトロピーを含むサイズに依存する磁気現象は,基本的な理解と潜在的な応用にとって重要である.
- この研究は,ナノマテリアルにおけるサイズ,相,磁性との複雑な相互作用を強調しています.
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