Extinction effect during X-ray dynamic scattering in a Ge crystal having dislocation loops

Experimentally observed and studied was effect of extinction change of the diffraction line contrast at scattering of widely diverging X-ray beam on decomposing Ge-As solid solution. It is shown that the extinction effect is due to the competing growth of X-ray scattering on static inhomogeneities of crystal lattice while depressing the dynamic diffraction channel, and it represents itself most vividly in conditions of the ''weak'' Bormann effect, 1 < or approximately μsub(o)t < 10 μsub(O) is the conventional coefficient of X-ray absorption, t is the sample thickness) on the second stage of Ge-As ageing. A theoretical description of the phenomenon observed is proposed in the supposition of existing of two scattering channels, i.e. kinematic and dynamic. Theoretically calculated dependences of the function of diffraction line contrast describe satisfactorily the experimental data