Effects of a finitely permeable back layer on auxiliary pole reproduction of perpendicular recording

Abstract

Addition of a highly permeable back layer to anisotropic Co‐Cr magnetic media has produced very high density digital recording performance in perpendicular recording systems using main pole/auxiliary pole heads. Direct calculations of the reproduce flux sensed by the auxiliary pole are presented as a function of back layer permeability and thickness. Calculated results show a slight shielding of the reproduce flux by the back layer and are in good agreement with experimental data. Simple reluctance models are developed which show the function of the back layer in improving reproduce performance.