Influence of magnetic field on the tunneling current in magnetic 10-nm-scale point contact junctions using tunneling atomic force microscopy

Point-contact junctions were fabricated by contacting an atomic force microscope (AFM) cantilever with a soft magnetic material coating on to [Al-O barrier/Fe3O4 half-metal] films using a tunneling AFM. The observed distribution of tunneling current through a thin barrier of Al-O in specimen point-contact junctions was influenced by the strength of the applied magnetic field and by the quality of the barrier at a measured position. Magnetization of the magnetically soft coating on the AFM cantilever was easily affected with alignment along the applied H direction, even when the contact size was as small as several tens of nanometers.