固态分子动力学研究一个包含铁电的: [(2,6-diisopropylanilinium) (([18]皇冠-6) ]BF4
Heng-Yun Ye1, Shen-Hui Li, Yi Zhang
1Ordered Matter Science Research Center, Southeast University , Nanjing 211189, P. R. China.
Journal of the American Chemical Society
|June 24, 2014
概括
分子动力学变化驱动新的[18]皇冠-6化合物中的铁电相变. 缓慢的分子旋转和离子滚动诱导了通过亚晶格移位的对称性破坏和自发极化.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 分子材料中的铁电相变通常涉及复杂的分子动力学.
- 了解分子运动是如何发生的,即使是没有直接二极子时刻重定向的分子运动,也会触发对称性破坏,这对于设计新的铁电材料至关重要.
- 分子铁电材料具有可调节的特性,并有可能用于新的电子应用.
研究的目的:
- 为了研究基于 [18]crown-6 的宿主-客人纳入化合物的铁电性质, [(DIPA) (([18]crown-6) ]BF4.4.
- 阐明分子动力学,结构对称性和这种材料中的自发极化之间的关系.
- 为了解新兴分子铁电学中的结构属性相关性做出贡献.
主要方法:
- 对BF4的系统性表征,包括介电测量,火电和第二和生成 (SHG) 响应.
- 可变温度单晶X射线衍射以确定结构变化.
- 固态核磁共振 (NMR) 光谱检测分子动力学.
主要成果:
- [(DIPA) (([18]皇冠-6) ]BF4表现出优秀的铁电行为,具有很大的介电异常,火电,SHG反应和明显的极化电场歇斯底里循环.
- 可变温度研究表明, [18]皇冠-6分子旋转和BF4离子翻转的减速导致对称性破裂.
- 自发的极化是由于阴离子和阴离子子子网的相对移位而产生的.
结论:
- 该研究表明,特定的分子动力学 (旋转和翻转) 与 [18]皇冠-6纳入化合物中铁电的出现之间存在明显的联系.
- 这些发现强调了微妙的分子运动在诱导宏观铁电性质方面的重要性.
- 这项工作为基于主机-客户系统的新型分子铁电的合理设计提供了宝贵的见解.
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