Influence of Magnetostatic Interaction on the Magnetization Reversal of Patterned Co/Pd Multilayers Nanorings

We present a systematical investigation of magnetostatic interaction on magnetization reversal process for [Co(5 angstrom)/Pd(30 angstrom) multilayers nanoring arrays separated by various edge-to-edge interring spacing (s). We observed that the coercivity H-c and switching field distribution (SFD) are strongly dependent on both and number of multilayer repeats n. For a fixed n, the absolute SFD and both increase with increasing s. However, the normalized SFD (SFD/H-c) shows a non-monotonic variation, while a minimum value of the normalized SFD is observed at a critical s = 500 nm. The findings are strongly related to the magnetostatic interaction on magnetization reversal in nanoring arrays, which are further revealed by micromagnetic simulations together with magnetic force microscopy.