Abstract
The diffraction contrast produced by 90° ferromagnetic domain walls in X-ray transmission topographs is calculated. Two cases are considered: very low and very high normal absorption. The results indicate that the difference in contrast on walls having opposite signs of lattice tilt is due to the anomalous absorption and depends on the magnitude of normal absorption. These theoretical results are in agreement with the contrast observations in X-ray transmission topographs taken from Fe-3 wt%Si single crystal samples using different plate thickness and different radiations.