Transition from coherent rotation to curling mode reversal process in ferromagnetic nanowires

We have investigated the evolution in the magnetization reversal mechanism of lithographically defined Ni80Fe20 nanowire arrays with varied film thicknesses. The nanowire array of width 185 nm and spacing 35 nm were fabricated using deep ultraviolet lithography at 248 nm exposing wavelength. We observed a cross-over from coherent rotation to curling reversal mode when the thickness to width ratio >= 0.5. We have aided our understanding of the reversal process with theoretical modeling. A marked increase in the coercive field characterized the intermediate region between coherent rotation and magnetization curling.