Cross-track characteristics of shielded MR heads

Abstract

A three-dimensional micromagnetic model of the cross-track response of shielded magnetoresistive heads is presented in order to assess MR head performance in high track density recording applications. Both the down-track output pulse-width and the off-track output asymmetry decrease as the shield-to-shield separation decreases. For the same biasing level, the off-track asymmetry increases with the stripe height. Proper initialization is found to be crucial to the head response profile. If the horizontal magnetization components of the MR and the adjacent layer are not in an anti-parallel state, larger off-track asymmetry occurs. For improperly initialized heads, side-reading noise arises from local reversal of edge magnetizations in the un-pinned layer, which could be reduced by the presence of ideal shields.