Micromagnetics and eddy current effects in magnetic recording heads

We developed a micromagnetic modeling program for magnetic recording head analysis, taking eddy current effects into account, and studied the 1-GHz high-frequency response. When gyromagnetic precession is dominant with a small damping parameter of 0.01, the eddy current field causes the delay of the response, but the head field intensity increases a lot, compared to the no eddy current case, because the eddy current field cancels the precessional motion and improves the magnetization alignment. Since magnetic soft films have an intrinsic small damping, low-resistivity material is preferable for high-end magnetic recording heads. Index Terms--Eddy current, finite-element method (FEM), magnetic heads, micromagnetic modeling.