Sensitivity distribution asymmetries in magnetoresistive heads with domain control films (abstract)

Abstract

Suppression of the sidetrack reading behavior is important in achieving⋅high track-density recording with a magnetoresistive head. In the present work, we investigate the sensitivity distribution profiles of MR heads through experimentation using a microtrack technique1 and computer simulation. Shielded, soft, adjacent-layer-biased MR heads with 3∼6−μm-wide tracks are used. The ends of the MR elements are coupled to antiferromagnetic or hard ferromagnetic films for domain control. In the simulation based on the Landau–Lifshitz–Gilbert equation,2 the magnetization configurations in the MR elements of the domain stabilizing films are calculated to analyze the sensitivity distribution. The measured sensitivity profiles in all cases have asymmetries that are reversed when the sensing current direction or the magnetization direction of the MR element is reversed. These results agree with the simulation. The asymmetries of sensitivity profiles are explained by the magnetic poles at the domain control film edges and at the transverse edges of the element which generate a diagonal demagnetizing field distribution in the sensing region.