Mapping of the magnetic leakage fields from nanoparticles by Fresnel projection microscopy

The magnetic leakage fields from the poles of magnetic nanoparticles down to 105–106 spins, isolated or situated at the edges of clusters, are observed with Fresnel projection microscopy by the presence of interference fringes generated by the magnetic phase shifts in the imaging electron beam. The particle shapes and localization of fringes are imaged simultaneously with nanometer spatial resolution at ∼200 V.