Electron microscopy

With optical microscopes (light microscopes) the acchievable resolution depends on the wave length of the light. Since fast electrons have a significantly lower wave length than visible light, a significantly highter lateral resolution can be achieved by using an electron microscope.

Similar to the reflected- or trasnmitted-light mode in light microscopy, there is a distinction between scanning electron microscopy (REM) for exmining sample surfaces and transmission electron mikroscopy (TEM) for examining the €žinterior of samples€œ (e.g. boundary surfaces, diffusions etc).

Different signals (secondary electrons (SE), back-scattered electrons (RE),  x-ray) are caused by the interaction of the primary electron beam and the sample which can be captured with special detectors. These make it possible to gather extensive information on the sample (see electron beam analysis).

Additional references:

Energy dispersive x-ray spectrometry
environmental scanning electron microscopy
scanning electron microscopy
scanning tunneling microscope
wave length-dispersive x-ray spectrometry