Quantitative shadow technique for the investigation of magnetic domain wall widths

Quantitative measurement of domain wall widths in a magnetic thin foil of Nd2Fe14B and a patterned Ni88Fe12 Permalloy element is obtained by the analysis of coherent shadow deformation of an electrostatic biprism in an electron microscope. Information related to the phase gradient in the direction perpendicular to the biprism is extracted by comparing the recorded shadow images with simulations computed according to the experimental electron optical configuration and by varying a single free parameter: the domain wall width. We demonstrate the feasibility of such experiments and the usefulness of the technique for characterization of magnetic features at different length scales.