ON THE THEORY OF HUANG X-RAY-SCATTERING CAUSED BY POINT-DEFECTS IN HEXAGONAL CRYSTALS

The theory of Huang scattering of point defects in hexagonal crystals is treated. The concept of ''elementary defects'' which is based on gr oup theoretical methods is introduced. From this point of view, point defects in hexagonal crystals can be understood as unique superpositio ns of three types of incoherent elementary scattering defects. These e lementary defects reflect characteristical defect symmetries. This con cept yields a simple analytical expression for the Huang intensity in the case of arbitrary scattering vectors. The derived intensity functi on may be a useful tool for the investigation of defect structures in h.c.p, metals by Huang scattering measurements.