Application of atomic force microscopy to magnetic materials

A new method of imaging the surface on a submicron scale is described and the observation of magnetic domain walls presented. Measurements in air on Co–Ni recording media and rapidly quenched Fe–Nd–B are shown. A resolution of better than 10 nm is achieved. This magnetic microscope is based on the idea of measuring magnetic forces with the recently developed atomic force microscope (AFM). Forces acting on a tip are recorded by the measurement of the deflection of a lever to which this tip is attached. The lever is made from a metallic foil with an integrated, electrochemically etched tip. Different measurement modes of the magnetic microscope are described. The images obtained by the AFM using a para‐ and ferromagnetic force sensor and by the STM are compared. Furthermore, results are compared with previous studies by the scanning electron microscope with polarization analysis and the Lorentz electron microscope. Finally, a concept is presented by which magnetic, topographic, and chemical information is simultaneously acquirable.