Development of TEM specimen Holder Enabling Atomic Level Observation under One Atomospheric Pressure

开发可在一个大气压下进行原子水平观察的 TEM 样品架

基本信息

批准号：
12555017
负责人：
TAKAI Yoshizo
金额：
$ 5.12万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555017/
关键词：
Transmission Elecron Microscope Environmental Cell Bio Medical Sample Sealing Film Aberration-Free observation Phase Electron Microscope Spherical aberration Correction 位相像観察

项目摘要

An environmental cell (EC) technique is useful for the study of hydrated and catalytic specimens etc. under various environmental atmosphere by a transmission electron microscope. In the present study, we have developed a film-sealed type EC which enables atomic level observation under one atmospheric pressure. The developed EC has the passages connecting the EC and the outside of the microscope column, therefore, the gas pressure of the specimen environment can be controlled by adjusting the gas flow. In general, the EC must have some windows for electron beam passage and some sealing films covering the windows are necessary to protect the gas leakage into the microscope column. The most important component of the EC is the sealing film. The film must withstand above atmospheric pressure with maintaining properties such as high electron transmittance, amorphousness of the film and so on. In the present study, we succeeded to make a carbon film of 20 nm thick which,withstands the pressure of one atmospheric pressure or more. A buffer layer of triacetylcellulose (TAG) film of about 150 nm in thickness was sandwiched between the carbon film and the metal supporting grid, which works very effectively to realize the resistance to the gas pressure difference. An apparatus to insert the TEM specimen holder with the EC was also developed and TiO2 powder sample was successfully observed at one atmospheric air pressure. By introducing reaction gas to the sample, catalytic behavior of TiO2 might be possible to observe in atomic scale. Precise evaluation on the achieved resolution is now under examining as a function of the atmospheric pressure and the thickness of the sealing film. Plasma induced by high speed electrons incidence sometimes gave damages to the observed sample, which is under investigation based on Monte Cairo computer simulations.

环境细胞（EC）技术可用于通过透射电子显微镜在各种环境气氛下的水合和催化样品等研究。在本研究中，我们开发了一种薄膜密封的EC，该EC可以在一个大气压下实现原子水平观察。开发的EC具有连接EC和显微镜柱外部的段落，因此，可以通过调节气流来控制样品环境的气压。通常，EC必须有一些用于电子束通道的窗户，并且需要一些覆盖窗户的密封膜来保护气体泄漏到显微镜柱中。 EC最重要的组成部分是密封膜。该膜必须承受以上的大气压力，并保持诸如高电子透射率，膜的无定形等性能。在本研究中，我们成功地制作了20 nm厚的碳膜，该薄膜承受一个或更大的大气压力的压力。将厚度约150 nm的三乙酰基纤维素（TAG）膜的缓冲层夹在碳膜和金属支撑网之间，该网格非常有效地实现了对气压差的阻力。还开发了一种用EC插入TEM样品持有人的设备，并在一个大气气压下成功观察到TiO2粉末样品。通过向样品引入反应气体，可以在原子量表中观察TiO2的催化行为。现在，对已达到的分辨率的精确评估正在检查，这是大气压力和密封膜厚度的函数的函数。高速电子发病率引起的血浆有时会损害观察到的样品，该样品正在基于蒙特开罗计算机模拟的研究中进行研究。