Advanced Materials Characterization Chapter 5 Transmission Electron Microscopy

Advanced Materials Characterization Chapter 5 - by Igor Bello

Transmission electron microscopy (TEM) has become a very powerful tool in experimental analysis of materials, chemistry, biology, electronics, and optoelectronic devices. TEM reveals not only morphology and defects of materials, but with additional integrated techniques, it enables us to study crystallographic structure and chemical composition at a very high spatial resolution. The technique called high resolution transmission microscopy (HRTEM) provides atomic resolution.

TEM consists of an assembly of an electron gun, a fluorescent screen/CCD camera, and electromagnetic lenses arranged in a vertical column. The electron gun is at the top of the column, while the CCD camera is at the opposite end of the column. Contemporary TEMs are equipped with modern digital cameras and frame grabbers. The frame grabbers are electronic systems that can capture a high-quality frame of analog or digital video frames.

The produced electron beam by an electron gun is accelerated by a high voltage down the column toward the screen/camera. The acceleration voltage is typically between 100 and 300 kV.