Analysis of perpendicular magnetic recording mechanism by finite element analysis combined with medium magnetization model

A new program for simulating magnetic write and read processes was developed, incorporating into the finite element method a model of curling mode magnetization in the perpendicular magnetic recording medium. That is, the curling mode was adopted as describing the mechanism of magnetization reversal in the fine crystal grains comprising the Co-Cr recording layer, and the magnetization vector is computed stochastically, with the dispersion in the easy axis of magnetization and the anisotropy field represented by a probability density function. Such finite element analysis simulations incorporating a magnetization model are capable of addressing complex magnetization processes within the recording medium. This method takes into account magnetic interactions between head and medium which depend on saturation in the head and medium soft magnetic layer and on the strength of magnetization in the medium, effects not accounted for by the scalar potential method; it also incorporates magnetization by rotation, which cannot be included in ordinary finite element analysis. As a result, this approach enables highly accurate, quantitative computer simulations of magnetic read and write processes which take into account not only such magnetic properties of the recording medium as the Co-Cr layer coercivity and saturation magnetization, but magnetic properties of the head and the medium backing layer as well, such as permeabilities and saturation flux densities.