Modeling Perpendicular Magnetic Multilayered Oxide Media With Discretized Magnetic Layers

Micromagnetic models derived from the Landau-Lifshitz-Gilbert equation and its derivatives are important tools that can be used to understand error rate performance in magnetic recording systems. With increasing linear density in perpendicular magnetic recording (PMR), exchange coupled composite (ECC) media is required and optimizing the cap layer is essential to achieve good recording performance [1]. It is important to model the cap layer and thin oxide layers accurately to obtain a reasonable evaluation of recording performance, especially when the bit length is approaching the grain pitch. The often-used macro-spin model may not be sufficient to describe the semi-continuous nature of the cap layer. The macro-spin model may lead to discrepancies with the experimental data in many key areas such as resolution, non-linear effects [2], and particularly SNR at high linear densities. Here, we evaluate the performance of a fully discretized cap model for ECC media. We compare simulation results of two discretized cap models to the traditional macro-spin model as well as to experimental data.