First-Order Reversal Curves Diagrams of Ferromagnetic Soft Nanowire Arrays

First-order reversal curves (FORC) diagrams map the statistical distributions of magnetic hysterons, based on their critical fields (H _c) and local interaction fields (H_u), throughout the magnetization reversal. This technique has been adapted to soft nanowire arrays deposited into alumina templates, with axes perpendicular to the template plane (diameter=50--175 nm, length=5--60 mum). From the topology obtained, the intrinsic physical properties of the array can be determined, notably the coercivities of individual nanowires and the interaction field at saturation. However, the FORC diagram may also yield information on other properties, such as the existence of a distribution of wire lengths