Effect of Nanolithography Defects on Switching Behavior of Ferromagnetic Elements

This study employed nanolithography to create geometric defects in magnetic components. Nanolithography is a technique that utilizes an AFM probe to exert pressure on the sample surface and follow specific paths, enabling the creation of two-dimensional patterns on a thin film. We fabricated a permalloy disk using electron beam lithography and then used multiple scrapes to remove an area of devices. Subsequently, each iteration was observed using a MOKE microscope to analyze its impact on magnetic reversal behavior. The magnetic hysteresis loops show no significant changes during small edge area engraving for a circular disk. As the removed edge area increases, the appearance time of vortices decreases. In addition, we fabricated a magnetic wire with an injection pad and created notches on the wire using electron beam lithography and nanolithography, respectively. We investigated the depinning behavior of magnetic domain walls behind these notches. Experimental data identify significant differences in depinning fields for defects produced by the two distinct processes.