Forbidden Reflections in the Single Crystal Si Substrate
单晶硅衬底材料中的消光衍射

In the conventional theory of X-ray diffraction, th e 4n 2 reflections are forbidden such as Si(200) and Si(222) reflection.Howe ver,these sorts of the forbidden reflections are observed in single crystal Si o r Si-based materials.When the anharmonic contribution to the temperature factor and the antisymmetric bonding charge distribution are taken into account,the re lative intensities of the forbidden (200) and (222) reflections are calculated,r espectively.It is found that the calculated values are in agreement with the obs erved values by using XRD technique.The results also indicate that forbidden (20 0) and (222) reflections can occur mainly for the antisymmetric charge density d istribution at room temperature.And the applications of forbidden reflections ar e emphasized in the XRD analysis.