Adjacent track interference analysis of shielded perpendicular writers

In order to achieve high track density in perpendicular recording, write-field leakage from the main pole to adjacent tracks needs to be minimized. We used a 3-D finite-element method to investigate the optimal writer design, which minimizes fringing fields. We also confirmed the results using experimentally by studying adjacent track interference (ATI) on a spinstand. According to both modeling and experimental data, we found that ATI performance can be clearly improved with a wrap-around-shielded (WAS) writer while maintaining enough write-ability. In order to reduce the fringing field, a WAS having thick throat, high permeability and high saturated magnetic flux density was required. We also confirmed that variations of ATI performance due to flare length distributions can be effectively suppressed with the WAS writer.