ABSTRACT
The transmission electron microscope (TEM) provides detailed structural information at levels down to atomic dimensions. There are two types of TEM: the conventional TEM (CTEM) and the scanning TEM. The modern CTEM is provided with several sets of electromagnetic coils which can be used to translate or tilt the electron beam. In the case of a single crystal the pattern represents a section through the reciprocal lattice plane that lies perpendicular to the incident electron beam. The interpretation of electron diffraction patterns is usually more straightforward than of X-ray diffraction patterns. The dynamical theories of electron diffraction attempt to take into account multiple scattering and the attenuation of the electron beam in the forward direction as it passes through the specimen. The specimen stage must permit translation of the specimen to facilitate the selection of the area to be observed.
