Fast reversal dynamics in perpendicular magnetic recording media with soft underlayer

Abstract

Reversal dynamics in perpendicular magnetic recording media is investigated using finite element micromagnetic simulations. The results show that gyromagnetic precession plays an important role during the magnetization reversal of both the soft underlayer and the data layer. Magnetization reversal within the soft underlayer starts at positive applied field due to its low anisotropy and high demagnetization field. The switching of the data layer starts at an applied field of about -0.3 H k,DL, where H k,DL is the anisotropy field of the data layer. At finite temperature, thermal activation reduces the dynamic coercivity. However, this effect is smaller than the change of the dynamic coercivity found by varying the Gilbert damping parameter, α. Media dynamic coercivity was found to increase significantly when α was decreased from 0.1 to 0.01. © 2002 American Institute of Physics.