First-order reversal curves analysis in nanocrystalline ribbons

Differential analysis based on first-order reversal curves (FORC) is being increasingly used to study the internal interactions in magnetic systems. Traditionally, this technique has gone hand in hand with Preisach-type models which, although succeeding in describing weakly interacting systems, are not applicable to nanostructures or polycrystalline systems characterized by strong internal interactions. This paper is aimed at contributing to the physical understanding of the complex FORC diagrams of strongly interacting systems with a macromagnetic model based on a mean interaction field and a distribution of switching fields as intrinsic elements. The proposed idea is used to explain the FORC patterns of nanocrystalline Co-based systems.