Write field analysis in perpendicular recording using three-dimensional micromagnetic simulation

Abstract

A three-dimensional micromagnetic perpendicular recording model is developed to study the effect of magnetic properties and head geometry on the write head field. For parameters characteristic of 200 Gbit/in.2, the maximum write field is about 0.73 Bs. Thirty percent of this field is due to neck saturation. Calculated head field gradients at track center agree well with the theoretical Westmijze field. The maximum write field is independent of the SUL thickness for thicknesses greater than the track width. At an SUL thickness of half the track width, the field decreases by 10%, and thereafter decreases rapidly.

Effect of Damping on the Time Variation of Fields Produced by a Small Pole Tip With a Soft Under Layer

“…When the damping of the system is small and energy dissipation to the lattice occurs over a long time, these excitations allow the average magnetization to reverse in shorter times as compared to the coherent case, provided the field amplitude is sufficient [3]- [5]. As the damping parameter is decreased we observe an increase in the amplitude of the variation of the magnetostatic field about its equilibrium.…”

Read and write processes, and head technology for perpendicular recording

“…[47]. The figure shows micromagnetic simulation results for the write field as a function of write pole width for a given HMS value, with all other dimensions kept constant [47]. As can be seen from the figure, the write field decreases monotonically with the reduction of the write pole width.…”

“…These two different responses are from two different assumptions, whether the surface magnetization is perpendicular to the charge surface or perpendicular to the medium surface, respectively, when the write pole is saturated. The results show that given different assumptions about the write head saturation, there exists an optimal angle to achieve maximum on-track field [47][48][49][50][51]. Note that as previously argued, achieving maximum on-track field is only one aspect in optimizing the slope angle.…”

“…7(a) illustrates the first consequence of the breakdown of scaling given by Ref. [47]. The figure shows micromagnetic simulation results for the write field as a function of write pole width for a given HMS value, with all other dimensions kept constant [47].…”

Approaches to tilted magnetic recording for extremely high areal density

“…Among them, high sensitivity of signal-to-noise ratio (SNR) on the switching field distribution (SFD) of magnetic grains in a fully or nearly fully decoupled media during the recording process is one of the main physical concerns during its real implementation [3], [4]. The low writing field efficiency of a real single pole head is another concern that may block the final writing capability of the high coercivity media [5]. To alleviate the above problems, tilted magnetic recording is recently attracting more attention.…”