In-situ manipulation of ferroelectic structures at atomic level

铁电材料的特点是在居里温度以下没有外场的情况下存在有限电极化。这些材料倾向于形成畴，即具有相同极化方向的区域。施加电场可以改变这些材料的自发极化。因此，控制畴的开关，即极化方向，对于未来在机电设备中的应用至关重要。最近，已经开发了用于透射电子显微镜的微机电系统，允许铁电材料电偏和/或原位加热，在可控的电/温度条件下产生样品的实时信息。此外，可以直接将原子水平动力学与电学性质和温度联系起来。该项目的主要目标是在原子水平上对铁电结构进行原位操纵。这将需要扫描透射电子显微镜和映射算法的结合，以在不同温度下对材料进行有偏和无偏的极化分析。

Ferroelectric materials are characterized by the existence of a finite electric polarization in absence of an external field below the Curie temperature. These materials tend to form domains, i.e. areas with the same direction of polarization. The application of an electric field can change the spontaneous polarization of these materials. Therefore, control over the switching of the domains, i.e. the polarization direction is essential for future applications in electro-mechanical devices. Recently, micro-electro-mechanical systems have been developed for transmission electron microscopy, allowing ferroelectric materials to be electrically biased and/or heated in-situ, producing real-time information on the specimen under controllable electrical /temperature conditions. Additionally, it is possible to directly correlate atomic level dynamics to electrical properties and temperature. The main objective of the project is the in-situ manipulation of ferroelectric structures at atomic level. This will require a combination of Scanning Transmission Electron Microscopy and mapping algorithms to carry out polarization analysis of the material with and without biasing at different temperatures.