結晶構造とナノスケールのBaTiO3のパラ電気から鉄電気への相変化
Millicent B Smith1, Katharine Page, Theo Siegrist
1Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
Journal of the American Chemical Society
|May 9, 2008
まとめ
ナノ結晶バリウムチタネート (BaTiO3) は,26nmまで電鉄性能を保持しています. しかし,より小さな粒子は,分散した相移行を示し,歪み相合性が低下していることを示します.
科学分野:
- マテリアルサイエンス 材料科学
- 固体物理 固体物理学
- ナノテクノロジー ナノテクノロジー
背景:
- バリウムチタナート (BaTiO3) は,電子工学における応用を持つ重要な鉄電気材料です.
- BaTiO3のサイズに依存する性質を理解することは,先進ナノマテリアルの開発に不可欠です.
- BaTiO3におけるパラ電気から鉄電気への相転換は,構造の変化に敏感である.
研究 の 目的:
- 異なるサイズのナノ結晶のBaTiO3におけるパラ電気から鉄電気への相変化を調査する.
- 異なるサイズのBaTiO3粒子の室温構造を解明する.
- 粒子の大きさの影響が相変化の行動や構造的歪みに及ぼす影響を判断する.
主な方法:
- 温度に依存するラーマン光譜法.
- 粉末X線微分法 (XRD).粉末X線微分法.粉末X線微分法.粉末X線微分法.
- シンクロトロンX線散射,リートヴェルド精細化とペア分布関数 (PDF) 解析を含む.
主要な成果:
- 鉄電四角形相は,最小のBaTiO3粒子 (26 nm) にさえも観測される.
- 小粒子の気温では,相変遷は散らばり,散らばったBaTiO3.3の急変異とは異なり,相変遷は散らばります.
- 構造的歪みは粒子の大きさが減少するにつれて増加し,平均立方体の構造への傾向が伴います.
結論:
- BaTiO3の構造的歪みは,異なる粒子のサイズで強固である.
- 構造的歪みの一貫性は,より小さなナノ結晶粒子において著しく低下する.
- これらの発見は,特定のアプリケーションのためにBaTiO3ベースのナノマテリアルの特性を調整するために重要である.
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