Micromagnetic track profile asymmetries in dual magnetoresistive heads

An appropriate 3-D micromagnetic model of a shielded, finite stripe height, dual element magnetoresistive (MR) head is developed. It is shown that asymmetric bias profiles in the cross track direction arise from uniform bias magnetic fields. These asymmetric bias profiles appear in addition to the previously reported anisotropic signal flux propagation that occurs with respect to MR sensor width edges. For the case studied, the peak response of the dual MR sensor is 1.5 times that for the single film. Peak-to-peak voltage asymmetry varies considerably for the single-film MR as the line source alignment is changed. However, the differential sensor exhibits very small peak asymmetry for all alignments. Finally, it is shown that for the case studied, the 50% amplitude track width of the dual MR sensor is about 26% broader than that for the single MR response curve.>