Diagram of the states in arrays of iron nanocylinders

The magnetic states of two-dimensional cylinder arrays of iron are studied as function of thickness, diameter, and separation by means of numerical micromagnetics. The corresponding diagram of the states for cylinders with thickness and diameter in the nanoscale regime is presented. The diagram is composed of regions with a single minimum of the free energy, relevant for applications, and regions with multiple minima. The effect of the magnetostatic coupling is highlighted by comparing the state diagram for cylinders with 10 nm perimetrical separation with the one for isolated cylinders.