Untersuchungen über Umweganregung und ihre Vermeidung am Beispiel des Na2BeF4*

Abstract

Measurements of x-ray-diffraction intensities of a Na₂BeF₄ single crystal were influenced by “Umweganregung” (multiple reflection) in the range of weak and medium peak intensities. A computer program was developed to calculate optimal settings for a two-circle diffractometer in order to avoid simultaneous reflections of considerable intensity contributions. The calculations of the program include primary-radiation divergence. Many “Renninger” peaks at positions of systematic absent reflections were observed and experimentally examined. At about 15% of the reflections in the range of copper-Kα radiation “Umweganregung” was detected.