Dynamische Theorie der Röntgen-Strahl-Interferenzen an schwach verzerrten Kristallgittern

Abstract

The propagation of X-rays in weakly deformed crystal-lattices with excitation of a BRAGG-Reflexion is treated geometrical-optically. By connecting LAUE’S dynamical theory with the WANNIER-SLATER electron theory one expands the wave function in WANNIER functions and obtains approximately a transformed form of the wave equation. From this equation the geometricaloptical approximation is derived by going to the limit of infinitely small wave-length and lattice constants. In this way it is clarified that this approximation is closerelated to the effective mass theory of electrons