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.
Bibliographical noteFunding Information:
This work was supported by Seagate Technology and the Minnesota Supercomputer Institute. M. Patwari would also like to acknowledge the input and advice from J. Gadbois, M. Kief, K. Duxstad, C. Rea, R. Fry, P.-L. Lu, A. Nazarov, P. Czoschke, Y. Chen, and K. Allen on this project.
Copyright 2010 Elsevier B.V., All rights reserved.
- Erase after write
- On track erasure
- Perpendicular recording
- Perpendicular writer