THE EFFECT OF ABSORPTION ON THE INTEGRATED REFLECTIVITY OF DEFECTIVE SINGLE-CRYSTALS

An empirical relationship has been developed that relates the product of the X-ray mass absorption coefficient mu and the extinction distance xi from dynamical diffraction theory to the ratio of the integrated reflectivities that are predicted from both the kinematic and the dynamical theories of X-ray diffraction. The 111, 222 and 333 integrated reflectivities from samples of CdTe with significantly different etch-pit densities were then measured and analyzed in light of this relationship. The integrated reflectivity measurements suggest that the crystals are of similar crystalline perfection, while the etch-pit densities imply that one crystal is much more perfect than the other. The apparent similarity of the two samples in the diffraction experiments is interpreted with respect to a linear dependence of the ratio R(dyn)/R(kin) on the parameter In mu-xi. This result is consistent with the defect structures of the crystals observed using X-ray topography.