Longitudinal Write-Process Modeling Including Measured Angular-Dependent Coercivity

Recent angular VSM measurements indicate that the remanent coercivity of various types of longitudinal media has an applied field angular dependence that approximates the behavior of Stoner-Wohlfarth particles with easy axes oriented isotropically in-plane. This is in contrast to the Kondorsky style switching (in-plane field, domain wall switching) inherently assumed in most models of the write process. In this article, we incorporate the measured angular dependent switching into a Williams-Comstock style write model. We find that the vertical spacing dependence of the transition width or "a" parameter can be much lower than that expected when only the in-plane component of the head field participates in switching the media. This phenomena is verified experimentally by writing at different spacings and reading at a constant spacing. We find that the experimental data can only be matched if the measured angular dependent switching is taken into account. (C) 2003 American Institute of Physics.