Magnetization reversal mechanisms in diamond-shaped Co nanomagnets

We investigate the magnetic properties of single layer and pseudo-spin valve Co diamond-shaped nanomagnets fabricated using deep ultraviolet lithography. We have performed a systematic investigation of the effect of film thickness on the magnetization reversal process of single layer Co nanomagnets. We observed that for t <= 10 nm, the reversal process is dominated by spin rotation in contrast with vortex nucleation and annihilation for thicker Co nanostructures. By exploiting the thickness dependence in single layer Co nanomagnets, pseudo-spin valve nanostructures with two Co layers thickness of distinct switching field separated by a Cu spacer layer were fabricated. We observed that the multilayer Co nanostructures display unique magnetic properties, which are greatly influenced by the Cu spacer layer thickness. Our experimental results are in reasonable agreement with simple micromagnetic simulations.