Portal de Periódicos da CAPES

Transmission Electron Microscopy

2008; Elsevier BV; Linguagem: Inglês

10.1002/9780470823002.ch3

1873-4189

Yang Leng,

Advanced Electron Microscopy Techniques and Applications

There are two main types of electron microscopes: transmission electron microscopes (TEM) and scanning electron microscopes (SEM). The optics of the TEM is similar to the conventional transmission light microscope, while that of SEM is more like that of scanning confocal laser microscopes. This chapter introduces the basic working principles and features of transmission electron microscopes. High-voltage electron microscopy requires extremely expensive instrumentation, and also it may damage a specimen by generating microstructural defects in it during observation. Preparation of specimens often is the most tedious step in TEM examination. A common procedure for TEM specimen preparation is described. TEM can be operated in two modes: the image mode and the diffraction mode. In the diffraction mode, a pattern of selected area diffraction (SAD) can be further enlarged on the screen or recorded by a camera.