Spot Profile Analysis-Low Energy Electron Diffraction

A real surface is not perfectly periodic but has manyBSS52

 imperfections in the form of dislocations, atomic steps, terraces and the presence of unwanted adsorbedHP3150V

 atoms. This departure from a perfect surface leads to a broadening of the diffraction spots and adds to the background intensitySG2525AN

 in the LEED pattern.SPA-LEED is a technique where the intensity of diffraction beams is measured in order to determine the diffractionSN5406J

 spot profiles. The spots are sensitive to the irregularities in the surface structure and their examination therefore permits more-detailed conclusions about someMM74C10N

 surface characteristics. Using SPA-LEED may for instance permit a quantitative determination of the surface roughness, terrace sizes or surface steps.