Surface Roughness Influence on Neel-, Crosstie, and Bloch-Type Charged Zigzag Magnetic Domain Walls in Nanostructured Fe Films

Charged magnetic domain walls have been visualized in soft magnetic nanostructured Fe thin films under both static and dynamic conditions. A transition in the core of these zigzagged magnetic walls from Neel-type to Bloch-type through the formation of crosstie walls has been observed. This transition in charged zigzagged walls was not previously shown experimentally in Fe thin films. For film thicknesses t < 30 nm, Neel-type cores are present, while at t approximate to 33 nm, walls with crosstie cores are observed. At t > 60 nm, Bloch-type cores are observed. Along with the visualization of these critical parameters, the dependence on the film thickness of the characteristic angle and length of the segments of the zigzagged walls has been observed and analyzed. After measuring the bistable magneto-optical behavior, the values of the wall nucleation magnetic field and the surface roughness of the films, an energetic fit to these nucleation values is presented.