Micromagnetic recording model of pole-tip saturation and medium orientation effects at 100 Gb/in2

The recording process at 100 Gb/in(2) is examined through the use of a recently formulated micromagnetic model. The Finite Element Method is used to calculate the write head field, the Landau-Lifshitz-Gilbert equations are solved for the medium and a micromagnetic approach is used to model magnetoresistive play-back. Effects due to pole tip saturation as well as medium anisotropy distributions (orientation ratio) are emphasized. At higher currents, pole-tip saturation causes recorded tracks to be significantly wider than the physical dimensions of the writer. Narrow reader dimensions also limit the play-back signal. Both of these effects are significantly improved through the use of oriented media. Preliminary results using a novel technique to model transition noise are also reported.