Analysis of Magnetic Relaxation With Pre-Existing Nucleation Sites Based on the Fatuzzo-Labrune Model

Time-resolved magnetic domain patterns of (Co/Pt) and (CoFeB/Pd) multi-layers with a perpendicular magnetic anisotropy are observed by means of magneto-optical microscopy, from which magnetic relaxation curves are determined via a quantitative image analysis. Interestingly, it has been observed that the relaxation processes starting with pre-existing nucleation sites, as well as starting from a fully saturated state, are well explained based on the Fatuzzo-Labrune model, although the pre-existing nucleation sites significantly modify the magnetization reversal behaviors.