Home Electron microscopy

In the place of the light beam of a normal microscope electron beams are used, which are focussed with the help of elctromagnetical fields. One differentiates between two principal procedures:

1. TEM - transmission electron microcopy. Transmission electron microscopes require the preparation of films so thin that they are transparent to a beam of electrons with energies of roughly 200 kiloelectron volts. This means the film must have a thickness of only one, or a few, hundred nanometres (10-9 metre). Films of lighter elements, such as aluminum, can be thicker, while films of heavier elements, such as gold, must be thinner. 

2. SEM - scanning electron microscopy. A scanning electron microscope  uses a narrow beam of electrons (often of about 40 kiloelectron volts) that scans the surface of a sample and forms a corresponding image from the backscattered electrons or secondary electrons. No special surface preparation is necessary, and, since the depth of focus in an SEM is much greater than in an optical microscope, quite irregular surfaces, such as fractures, can be studied successfully. Useful magnifications range from 100 to 20,000. 

This page in German - Diese Seite in Deutsch
© 2004 Büro für angewandte Mineralogie · Dr. Stephan Rudolph · D-47918 Tönisvorst
These recommendations are believed to be correct. However, no guarantee of their accuracy is given. Therefore, purchasers shall make their own tests to determine suitability for their use. These products are offered for industrial and related uses (e.g. research and development) only. However the user must take the necessary precautions appropriate for products containing chemicals. This description does not imply the absence of any patents, the responsibility whatsoever solely rests with the user.