Impact of Media Design on Track Edge in Perpendicular Magnetic Recording

Abstract

As track density increases, it has become even more critical to understand the track edge. In this study, the impact of media design on the track edges in perpendicular magnetic recording has been investigated. This study shows that soft under layer thickness and intergranular exchange coupling have significant impact on both track edge erasure and write width. In the range we studied, head-tokeeper spacing and media coercivity have a strong impact on write width, but not on track edge erasure. On the other hand, media design does not impact transition curvature significantly. Experimental observations were supported by media micromagnetic modeling results and write field simulation using a finite element model. Analyzing the write bubble helps to understand the dependence of adjacent track encroachment on media design. Cross track profiles of various signal-to-noise ratio (SNR) components can provide valuable insights into different track edge mechanisms.