Simulation of Erase After Write on 2.4 T FeCo Solid Pole Writer

We have developed a multiscale fast Fourier transform (FFT) based micromagnetic model to simulate erase after write (EAW) for a 2.4 T FeCo solid pole writer. The simulated remnant state of the writer showed vortices at the pole tip, break and paddle regions that qualitatively match an experimental MFM image. Dynamic responses show that EAW worsens with a longer breakpoint. Sensitivity of EAW with breakpoint is in good agreement with experimental data. We also find that cross track anisotropy reduced EAW risks; however, perpendicular anisotropy is detrimental to EAW. Simulations indicate that EAW risks may be substantially reduced if a demagnetization pulse of polarity opposite to that of the last write is applied to the writer.