应磁学与磁性材料教育部重点实验室暨物理科学与技术学院邀请，台湾新竹清华大学陈福荣教授于2017年6月6日-15日来我校进行学术交流并做学术报告，欢迎参加！

报告时间：2017年6月7日（星期三）上午10:00

报告地点：格致楼5004报告厅

报 告 人：陈福荣教授

报告题目：Low Dose Electron Holography toward Atomic Resolution Tomography for Soft Materials: Addressing Feynman's Dream

报告摘要

The ultimate goal for materials scientists is to understand the functions and to control the properties of materials. Richard Feynman gave the implication that the“atom”in 3D is the best alphabet for this purpose. The simplest example is the band-gap energy and mechanical energy of the so-called 2D material graphene can be modified due to the existence of intrinsic rippling and of externally applied strain deviates the atoms in graphene sheet into 3D. The mechanical and electronic properties of graphene are therefore encoded in the 3D positions of atom. Another way to deduce the physical properties of nano-object is to look at the dynam-ics with high time resolution. In my talk, I will first demonstrate the electron holography can be first reconstructed from a focal series of low voltage and low dose high resolution images. The name of“holo-”means“whole”in Greek. I will discuss the electron channeling theory that a hologram contains 3D atomic structure of a nano-object. And then I show how the 3D atomic resolution tomogram can be reconstructed from a hologram. The reconstructed atomic resolution tomogram of nano-bridge Au, wedge Ge and the nano-cube MgO will be shown. Futhermore , I show the result of electron beam induced dynamics of defect coalescence and long range rippling in graphene which strongly influence its mechanical and electronic prop-erties that are important for possible future applications.

Finally, I show the our instrumentation development of a low voltage/ environmental table top electron microscope toward bringing all theories and methodologies of low dose electron holography shown above into a compact system integrated with self-designed aberration corrected electron optics. The final remarks will end with a development migrating toward to build an ultrafast electron microscopy for the dynamics of the soft materials at high spatial resolution.

陈福荣教授简历

陈福荣，台湾新竹清华大学工程与系统科学系终身特聘教授，工研院材化所顾问。1980年获台湾新竹清华大学材料科学学士，1986年获美国纽约州立大学石溪分校材料科学博士，1988年麻省理工学院材料科学博士后，1990年西北大学材料系研究教授。现任台湾清华大学工程与系统科学特聘教授。主要从事电子显微学——三维原子分辨率之tomography，电子光学系统仪器设计及制造等方面的研究。近年来获得欧洲显微镜学会2012年度杰出论文奖等。其最近关于Big-Bang Tomography原理的研究及相关的结果发表在Nature期刊上。2009-2013有25次国际会议特邀报告，2012年担任东亚电子显微镜会议成立及筹备委员。