3-D micromagnetic simulation of write field rise time in perpendicular recording

A three-dimensional micromagnetic perpendicular recording model has been developed to study the dynamics of perpendicular recording. The write field rise time, shape, and magnitude are investigated. At a data rate of 1 Gb/s, our simulation shows that after 1 ns, the dynamic write field, both the shape and the magnitude, are about the same as compared to the static write field. The magnetostatic field of the medium causes a maximum of 10% write field magnitude decrease in a hard transition. For a flux rise time of 0.2 ns, the head fields follow the reversal flux closely. For a flux rise time of 0.1 ns, both the head field rise time and the average magnetization at the air bearing surface (ABS) increase with decreasing damping constant. The results suggest that increasing the damping constant of both the write head and the medium and decreasing the throat height of the head is important for ultra-high-density recording.