透射电子显微镜空间分辨率综述

Review on the spatial resolution of transmission electron microscope

透射电子显微镜(transmission electron microscope,TEM)具有超高的空间分辨率,是化学、材料科学、物理学、生物科学等领域最重要的研究手段之一.影响TEM空间分辨率的因素众多,不仅包括电镜自身结构和成像原理等,还有样品性质等原因.为系统且全面地了解TEM分辨率的涵义、原理与应用,本文通过回顾TEM空间分辨率的发展历史,从理论上厘清了TEM空间分辨率的概念、物理涵义、影响因素和适用范围;从电镜装置角度,分别概述了电子枪、磁透镜、图像探测器和电镜内外部环境对空间分辨率的影响规律,以及单色器、像差校正器和新型图像探测器的发展现状;从实际应用角度,重点介绍了样品过厚、电子束损伤、积碳和原子振动等降低空间分辨率的作用机理及解决途径.本文可为非电子显微学研究者们正确使用TEM提供参考.

Transmission electron microscope(TEM) is one of the most important research tools in a wide range of research fields such as chemistry, materials science, physics, and biological science. There are many factors affect the spatial resolution of TEM, including not only the construction of electron microscope and imaging mechanism, but also the nature of the sample and other reasons. In order to systematically and comprehensively understand the meaning, principle and application of TEM spatial resolution, this paper firstly briefly describes the history of TEM spatial resolution advancement, and then theoretically clarifies the concept, physical meaning, influencing factors and application scope of TEM spatial resolution, then outlines the influence of TEM electron gun, magnetic lens,image detector and internal and external environment on the resolution, the development of monochromator,aberration corrector and new image detector from the perspective of electron microscope device. Finally, from the perspective of practical applications, the mechanism of resolution degradation due to thickness, electron beam sensitivity, carbon accumulation and atomic vibrations and the corresponding solutions are highlighted.