FM - solid state physics and physics of materials

FM.LEE - Low-energy Electron Diffraction (LEED)

This experiment is currently not available.

Low Energy Electron Diffraction (LEED) is a widely used method in surface analysis. If a crystal is cut along a certain plane the atoms at and near the surface will rearrange and change their relative positions with respect to the bulk position (surface relaxation and reconstruction). By bombarding the surface with low energy electrons (approx. 20 - 200 eV) and by observing the diffracted electrons as spots on a phosphorescent screen the surface crystallographic structure can be determined. The diffraction pattern will move as the electron energy changes, and the intensity of the spots as a function of electron energy reveals much about surface reconstructions. In this experimental lab course, an epitaxial Graphene sample is grown on top of a SiC-wafer. The growth process shall be characterized by the diffraction pattern observed in the LEED-experiment.

IV. Physikalisches Institut, B-1.105