X-ray topographic observations of 180° magnetic domain walls in (001) plates of nearly perfect iron-silicon alloy single crystals

Abstract

Contrary to generally-held views, 180° magnetic domain walls lying in the cube planes normal to (001)-orientation single-crystal plates of Fe + 3wt%Si can be detected by diffraction contrast on X-ray projection topographs by use of conventional experimental arrangements. Conditions for good observations are explained with illustrations. The dominant contrast appears at intersections of the 180° Bloch walls with the X-ray exit surface of the specimen and is generated by small localized deformations at these outcrops. The contrast is at best very weak, being only about 10⁻² of that generated by 90° domain walls.