Development of 3-D read/write simulation system for higher areal recording density

Recently, higher areal recording density of hard disk drive (HDD) is achieved by increasing not only linear density (bits per inch) but also track density (tracks per inch). Then, three-dimensional (3-D) read/write (R/W) simulation is necessary in order to design a high-density recording system by utilizing magnetic field analysis. In this paper, a 3-D R/W simulation system using the edge-based finite-element method (FEM) is developed by introducing the 3-D medium hysteresis model based on the ensemble of the Stoner-Wohlfarth (SW) particles. As it is not easy to apply the Newton-Raphson method for the nonlinear analysis of SW model, an underrelaxation iteration method is used. The effectiveness of the 3-D R/W simulation system is illustrated by applying to the magnetic field analysis of a SPT (single-pole-type) head/DL (double-layer) medium perpendicular recording system.