Magnetostatic interactions of single-domain nanopillars in quasistatic magnetization states

The magnetostatic interactions and the disorder in an array of cylindrical Ni particles have been quantified. Room-temperature magnetic force microscopy data were used to determine the dipolar energy/particle for first, second, etc., nearest neighbor particles with external magnetic fields applied along the cylinder axes. An Ising-type model, which includes a distribution of anisotropy energies, accurately replicates the experimental dipolar energy/particle data and the observed hysteresis loops. The technique provides a method to quantify the magnetic properties of a magnetic particle system.