Micromagnetic behavior of electrodeposited cylinder arrays

Arrays of cylindrical magnetic particles have been made using interference lithography combined with electrodeposition. The cylinders are made from Ni, Co, CoP, or CoNi, with diameters of 57-180 nm, aspect ratios of 0.4-3, and array periods of 100-200 nm. The remanent states of the cylinders correspond to single-domain "flower" states or to magnetization vortices depending on the particle size and aspect ratio. Experimental data are in good agreement with a magnetic-state map calculated using a three-dimensional micromagnetic model, which shows the remanent state as a function of particle size and aspect ratio. The interactions between the particles, and their switching-field distribution, have been quantified.