Diffraction of x rays at the far tails of the Bragg peaks. II. Darwin dynamical theory
Phys. Rev. B 49, 33 – Published 1 January, 1994
DOI: https://doi.org/10.1103/PhysRevB.49.33
Abstract
The Darwin theory of dynamical diffraction by crystals is extended to include the regions between Bragg peaks as well as situations of grazing and normal angles of incidence, i.e., the whole angular range extending from 0° to 90°. The modified theory reproduces the usual two-beam Laue dynamical theory in the close vicinity of the Bragg peaks, while in the regions between the Bragg peaks it predicts reflectivities in agreement with the kinematical theory. Many-beam effects due to all crystallographic planes parallel to the surface can be calculated in an extremely simple way making this approach particularly suitable to artificial multilayered structures. The weak scattering in the region where the far tails of two neighboring Bragg peaks interfere contains information about the phases of the structure factors.