X-RAY-DIFFRACTION PROFILES IN STRAINED CRYSTALS UNDERGOING ULTRASONICEXCITATION - THE LAUE CASE

A new approach for the calculation of diffraction profiles in strained crystals is developed, based on the visual concepts of the dispersion surface and Poynting vectors. By this approach, analytical expression s have been obtained for diffraction profiles for the case of a consta nt strain gradient without, as well as with, ultrasonic excitation. Ca lculations of acoustically induced modifications in diffraction spectr a explain in detail the anomalous dependence of integrated intensity o n ultrasound amplitude, a dependence that was recently found in the La ue scattering geometry.