Pulse distortion in MR and GMR playback heads

Distortion of the playback pulse shape due to saturation is studied via a 3-D micromagnetic model for both MR/SAL and spin-valve heads. The deviation from linearity is examined as a function of both the Mr/spl delta/ of the recording medium and the off-track position of the device. Playback voltages for isolated transitions of both polarities are calculated and their shapes are compared to linear references. The differences in structure between MR and GMR sensors result in very dissimilar distortions of the playback pulse shape under large applied fields.