Magnetostatic interactions and coercivities of ferromagnetic soft nanowire arrays studied by FORC diagrams

FORC (first-order reversal curves) diagrams are a relatively new experimental method for mapping statistical distributions of magnetic particles, based on their critical fields (H_c) and local interaction fields (H_u). This technique has been adapted to soft nanowire arrays deposited into alumina templates, with axes perpendicular to the template plane. From the topology obtained, the intrinsic physical properties of the array can be determined, notably the coercivities of individual nanowires and the local interaction field. However, the FORC diagram may also yield information on other properties, such as the existence of a wide distribution of wire lengths.