Experimental method for surface domain wall shape studies in thin magnetic cylinders

Thin magnetic cylinders are in focus of interest due to peculiar features of domain wall motion like absence of the Walker breakdown. Here, we propose an experimental technique based on magneto-optical Kerr effect that allows surface studies of a domain wall shape in thin microwires. Our setup is optimized for characteristic optical and magneto-optical features of thin magnetic cylinders. Time-resolved measurements of a magnetic contrast along the circumference of wire are used to reconstruct a three-dimensional image of a surface domain wall shape. Our measurements confirmed a tilted shape of domain wall, in agreement with previous observations of microwires with positive magnetostriction alloy. The experimental technique represents a new way for direct visualizations of a surface magnetism of thin cylinders in optical range.