Visualization of chemical reaction at an atomic scale by in-situ wave field restoration TEM method

2015 Fiscal Year Final Research Report

• Project/Area Number: 25286059
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Osaka University
• Principal Investigator: Takai Yoshizo 大阪大学, 工学(系)研究科(研究院), 教授 (30236179)
• Co-Investigator(Kenkyū-buntansha): KIMURA YOSHIHIDE 大阪大学, 工学研究科, 准教授 (70221215)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 高分解能電子顕微鏡 / 波動場再構成法 / その場観察 / 触媒反応 / 実時間焦点位置変調法 / 球面収差補正 / 焦点位置追尾 / 各種収差補正

Outline of Final Research Achievements

A wave-field restoration transmission electron microscope (TEM) system was newly developed for in-situ dynamic observation. In the new system, the change of focus accompanying the specimen drift was automatically corrected at a video frame rate, while performing simultaneous correction of spherical aberration, two and three fold astigmatism and coma aberration. The precision of the focus tracking was 0.3 nm, which was enough high to discuss the atomic structures in detail.
This technique was applied to study the graphen synthesis by cobalt nano particles, and the matrix crystal lattice of the particle and graphene sheets were separately observed. By analyzing the atomic structures, it became clear that there was a large distortion at near the surface area, where some precursors showing dark line contrast were often observed. The dynamic observation indicates that the graphene sheets are formed not on the topmost surface of the particle, but beneath the surface by a few atomic layers.

Free Research Field

工学