Writability of Perpendicular Recording Heads

Abstract

A comparative analysis of the writability of trailing pole (TP) and leading pole (LP) writers on double-layer perpendicular media was done by three-dimensional finite-element method modeling. The writability of the writers was estimated by a maximal strength of effective write field that was defined by the Stoner-Wohlfarth model. The LP writer revealed a weaker perpendicular but stronger longitudinal component of the write field and bigger write angle. The longitudinal component and write angle minimize the difference in writability between the two writer designs. The writers showed a different writability dependence on initial permeability and saturation flux density of a soft magnetic keeper. An increase of the keeper permeability improves the writability of the TP writer but marginally affects performance of the other. Modeling results suggest that the LP writer might outperform the writer with the TP if the keeper permeability is below 100. The TP writer did not show a noticeable sensitivity to the saturation flux density of the keeper in a range from 10 to 24 kG. The writability of the LP writer decreases monotonically with the saturation flux density of the keeper. Received results imply that the TP and LP writers might have different requirements to properties of the keeper material.