单晶放松器中类似泥的极性结构
Hiroyuki Takenaka1, Ilya Grinberg1,2, Shi Liu1
1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Nature
|June 16, 2017
概括
由于多域结构而非极性纳米区域模型, 放松铁电具有独特的特性. 这一发现为它们复杂的行为和材料设计提供了新的洞察力.
科学领域:
- 材料科学
- 凝聚物质物理学
- 固态化学
背景情况:
- 它具有极高的压电系数和高的导电性.
- 已建立的极性纳米区域模型未能完全解释放松器行为,阻碍了预测模型.
- 了解放松器的基本结构对于材料设计和应用至关重要.
研究的目的:
- 阐明放松铁电的基本结构及其与其异常性质的关系.
- 研究放松材料的空间和时间偏振相关性.
- 开发一个比极性纳米区域概念更准确的放松行为模型.
主要方法:
- 在原型Pb(Mg1/3,Nb2/3) O3-PbTiO3放松剂材料上使用了分子动力学模拟.
- 分析了材料中的结构,域大小和极化相关性.
- 将模拟结果与实验散射数据进行比较.
主要成果:
- 揭示了放松性质源于具有超小域大小 (2-10 nm) 的多域状态,挑战了非极性矩阵概念.
- 确定了放松极结构和水的泥状态之间的类比.
- 证明了高密度的低角度区域墙壁,与实验结果一致.
结论:
- 多域状态,而不是极性纳米区域,控制放松铁电行为.
- 这种新的结构理解解释了以前未被描述的放松器类.
- 为设计具有定制性质的新型放松材料提供基础.
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