报告人：刘  明 西安交通大学电信学院教授

时间：  2019年11月6日（周三） 上午9:30

地点： 中心校区知新楼C座C1113

邀请人：颜世申 教授

报告摘要：

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single crystalline ferroelectric BTO(BaTiO3), BFO(BiFeO3) and BTO/LSMO bi-layer membranes and with a damage-free lifting-off process. Our ferroelectric membranes can undergo a nearly 180° folding during in-situ bending test, demonstrating a super-elasticity and ultra-flexibility¹. We found that the origin of the super-elasticity was from the dynamic evolution of ferroelectric nanodomains in BTO and phase change in BFO. High stresses modulate the energy landscape dramatically and allow the dipoles to rotate continuously. A continuous transition zone is formed to accommodate the variant strain and avoid high mismatch stress usually causing fracture. BTO/LSMO shows a self-assembled spring shape due to the lattice mismatch as free-standing in the air. Such spring can undergo up 50% of the length change upon a mechanic forced is loaded. The phenomenon should be possible in other ferroelectrics systems through domain engineering. The ultra-flexible epitaxial ferroelectric membranes could enable many magnetoelectric applications such as flexible sensors, memories and electronic skins.

参考文献：

1. Dong, et al., Science 366, 475-479 (2019)

报告人简介：

刘明博士，2010年博士毕业于美国东北大学电子与计算机工程系，同年获“阿贡学者”资助，在美国阿贡国家实验室开展博士后工作。2013年9月，入职西安交通大学电信学院担任教授。入选国家及陕西省人才计划。刘明博士一直从事磁电耦合功能材料与器件的研究，迄今为止，在Science, Nat. Commun., Adv. Mater等发表SCI论文120余篇，撰写英文专著1部，申请或授权发明专利16 项。担任 Physics Letter A, Scientific Reports 和 JMIHI 编委，Sensors 客座编委，多次担任IEEE InterMag、MMM 等国际学术会议分会主席。主持“先进电子材料”重点研发计划子课题、教育部装发联合基金、基金委面上项目等10余项基金。

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