Pb (Ti,V) O3の強い極性ペロフスキットの巨大体積収縮
Zhao Pan1,2,3, Jun Chen1,3, Xingxing Jiang4
1Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
Journal of the American Chemical Society
|October 11, 2017
まとめ
研究者は,バナジウムに置き換えることで,鉛チタナート材料の負の熱膨張 (NTE) を強化しました. この研究は巨大な量縮小を達成し,先進的なNTE材料を開発するための新しい経路を提供しました.
科学分野:
- 材料科学
- 固体物理学
- クリスタルグラフィー
背景:
- 負の熱膨張 (NTE) は,重要な科学的および実用的な意味を持つユニークな物理特性です.
- 既存の材料でNTEを強化することは困難です. 化学的な改変がしばしばこの性質を弱めるからです.
- 改良されたNTEを備えた材料の開発は,高度な技術アプリケーションにとって極めて重要です.
研究 の 目的:
- 鉛チタネート (PbTiO3) ベースの材料の負の熱膨張 (NTE) を強化する.
- PbTiO3の鉄電気および熱膨張特性に対するヴァナジウム置換の効果を調査する.
- 重要なNTEを持つ材料を設計するための新しいアプローチを探求する.
主な方法:
- 鉛チタン酸 (PbTiO3) 格子にバナジウム (V) を化学的に置換してPb(Ti1-xVx) O3を形成する.
- 格子構造,極化,結合の変化を分析するための第一原理計算.
- 幅広い温度範囲における熱膨張特性に関する実験的特徴.
主要な成果:
- バナジウム置換は,自発的偏極化と共電結合の強化に関連して,Pb{Ti1-xVx) O3の格子四角性を (c/a) 顕著に促進した.
- Pb(Ti0.9V0.1) O3は,熱膨張の体積係数 αV = -3.76 × 10^-5 / °C (25-550 °C) で著しく強い非線形NTEを示した.
- 鉄電からパラ電の相移行中にPb{0.7V0.3) O3で ~3.7%の固有の巨大体積収縮が観察され,自発的な体積の鉄電収縮に起因した.
結論:
- この研究では,フェロ電気的性質を活用して,Pb ((Ti1-xVx) O3の強化されたNTEを達成しました.
- この発見は,鉄電性特性を調節することによって,新しいNTE材料を探索するための効果的な戦略を示しています.
- この研究は,NTE材料のファミリーを拡張し,大きく制御可能な体積変化を持つ材料を開発するための経路を提供します.
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