Magnetic nanostructure fabrication by soft lithography and vortex-single domain transition in Co dots

Micron/nano scale Co dot and wire arrays have been fabricated by soft lithography patterning with a resolution of 100 nm. Magneto-optic Kerr effect magnetometry combined with micromagnetic calculation is used to study, in detail, the vortex-single domain transition in the Co dots. A metastable single-domain state, which is stabilized by a local minimum energy induced by vortex nucleation, is demonstrated.