In scanning electron microscopy, the surface of a sample is scanned using a focussed, accelerated electron beam.

The primary electrons (PE) hitting the sample excite the atoms of the material, from which secondary electrons (SE) are released and escape into the sample chamber. These are attracted by a detector and processed into an image.

This method can be used to visualise the topography of the surface. Some parts of the primary electrons are also scattered back (backscattered electrons, RE). The number of backscattered electrons differs depending on the element, so that these can also be used as image information. This allows an element contrast to be achieved in the image.

Two scanning electron microscopes of the type LEO Gemini 982 and FEI Qanta 600 FEG are used at the Chair of Materials Science. The devices work with a Schottky-FE cathode and a single-lens system. This means that a maximum magnification of 700,000x or 1,000,000x can be realised even at a relatively low vacuum.
Both devices are equipped with a powerful EDX analysis (Energy Dispersive Xray analysis), which allows spatially resolved measurement of the element distribution in a sample. The Quanta also has an EBSD system. EBSD (Electron Backscatter Diffraction) can be used to determine the orientation of crystals on the surface of an object.