3. Advanced techniques

3.1 RHEED

RHEED (Reflection High Energy Electron Diffraction) is a grazing incidence electron diffraction technique. It can be used to study a wide range of surface phenomena in situ, such as crystal structure, surface reorganization, growth rate and mode, variations in lattice parameters and changes in surface roughness. An electron beam of 5 to 100 keV is directed onto the surface to be studied at grazing incidence (angle of less than three degrees). The electrons are then diffracted by the surface atoms (a few atomic layers), forming a diffraction pattern observed on a phosphorescent screen, which can be analyzed using a camera.

The RHEED is often accompanied by a differential pumping system for use under partial oxygen pressure, for example, and a steerable...