Reversal Properties of Write Head at Extremely High Density

In this paper, the dynamic response of a write head, with a single pole, symmetric shields, and driven by two symmetric five-turn driving coils, is analyzed. Triangular prism cells are introduced for accurate simulation of edges with slope, and comparisons of reversal processes are made between the heads with and without smooth edges. Simulation results reveal the phase shift of averaged magnetization of pole tip versus the current is more prominent for head with smooth edges. The reversal time is in the range of 0.49-0.09 ns with steady currents 5-20 mA, respectively, for heads with smooth edges. The reversal speed of the write head increases with larger damping constant, and there is an increasing phase shift meanwhile. The thickness of the soft underlayer (SUL) affects both the write field and the phase shift.