Fingerprinting Inhomogeneities in Recording Media Using the First-Order Reversal Curve Method

Understanding how interactions within magnetic systems affect the reversal process is critical to the development of magnetic recording media. Using the first-order reversal curve (FORC) method we demonstrate an ability to map out and uniquely identify magnetic recording media. We evaluate the interactions and intrinsic switching field distribution (SFD) in single layer and exchange coupled composite granular recording media. Landau-Lifshitz-Gilbert-based simulations are used to probe the roles lateral and vertical exchange interactions have on the distribution of reversal events. We find that there is an optimal value for these terms which maximizes homogeneity of the reversal behavior.