3D Simulation of Shielded-Type Spin-Valve Heads

Abstract

The characteristics of shielded-type spin-valve (SV) heads were simulated by using a micromagnetics model. The shields affect the magnetization distribution in the free layer which results in the reduction of the magneto-static coupling effect in the middle part of the free layer. For symmetric output waveform and high output level in the shielded-type SV heads, the pinned layer thickness is required to be as thin as possible to unify the magnetization distribution in the free layer along the MR height. A thick pinned layer cause a domain wall formation near the air bearing surface (ABS). Decreasing the MR height is effective for aligning the magnetization in the free layer toward the track width direction, and can improve the output waveform asymmetry. This is because the magneto-static coupling affects all over the free layer in the smaller height sensors.