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) multilayers with perpendicular magnetic anisotropy are observed by means of magneto-optical microscopy, from which magnetic relaxation curves are determined for. Interestingly, it has been observed that the relaxation processes not only from the saturated state, but also with pre-existing domains, are well explained based on the Fatuzzo-Labrune model. Full details of the relaxation behavior and subsequent microscopic domain patterns evolving from the pre-existing nucleation sites originated from the sub-structured magnetic domains are discussed.