Imaging of magnetic domains in thin Co/Pt and CoNi/Pt multilayers by near-field magneto-optical circular dichroism

A scanning near-field optical microscope (SNOM) was adapted to image magnetic domains by magneto-optical circular dichroism (MOCD), and was used to study magnetization reversal in sputtered Co/Pt and CoNi/Pt multilayers. Furthermore, local near-field MO hysteresis loops could be measured using the MOCD-SNOM technique. Artifacts due to structural defects and topography are discussed.