公开(公告)号：GB2275360A

公开(公告)日：1994-08-24

申请号：GB9401189

申请日：1994-01-21

Applicant: IBM

Inventor： CHEN MAO-MIN ,  GALLAGHER TIMOTHY JOSEPH ,  WANG PO-KANG

IPC: G01R33/09 ,  G11B5/03 ,  G11B5/39 ,  H01L43/08

Abstract: In a magnetoresistive (MR) read transducer 10 a soft magnetic layer 18 and an MR layer 24 extend over a central active region 12 and passive end regions 14, 16 of the transducer. A nonmagnetic spacer layer 22 separates the soft magnetic film layer 18 and MR layer 24 and extends over the central active region and at least part of both passive end regions. An antiferromagnetic layer 26 directly contacts the MR layer 24 only in the end regions and produces an exchange bias field between the antiferromagnetic layer 26 and the MR layer 24 that is oriented at a preselected acute angle to the longitudinal direction of the transducer, e.g. 40 - 450, thereby causing the MR layer 24 to be oriented at the preselected acute angle and the soft magnetic film layer in 18 the passive end regions being transversely oriented by magnetostatic coupling to the MR layer 24. To fabricate the transducer, the antiferromagnetic layer 26 is annealed in an external field above the Neel temperature to produce the canted exchange bias field. As a result of the canting, the magnetic moments of the central active region and the passive end regions are matched during a read operation.

公开(公告)号：DE69115939D1

公开(公告)日：1996-02-15

申请号：DE69115939

申请日：1991-01-25

Applicant: IBM

Inventor： JU KOCHAN ,  KROUNBI MOHAMAD TOWFIK ,  WANG PO-KANG

IPC: G11B5/33 ,  G11B5/39 ,  G11B5/58 ,  H01L43/08

Abstract: A magnetoresistive (MR) sensor (20) is centre tapped to provide the difference signals for servo operation on data and sum signals for the data information. The centre-tap (14) of the MR sensor is made of a high resistivity material compared to the resistivity of the MR element itself such as tantalum, Nichrome and carbon. Processes which can be used to produce the high resistivity centre-tap conductor include an insulator layer to define both the track width and the centre-tap conductor and a sequence which first patterns the MR sensor and then masks to define the conductor regions.

公开(公告)号：DE69018382T2

公开(公告)日：1995-10-12

申请号：DE69018382

申请日：1990-11-07

Applicant: IBM

Inventor： BEST JOHN STEWART ,  WANG PO-KANG

IPC: G11B5/596 ,  G11B21/10

Abstract: A method of positioning separate read and write heads in a disk file compensates for misalignment of the heads when reading and writing data on the disk. Two sets of servo information are generated for each track on the disk. These sets are radially displaced with respect to each other by a distance equal to the respective misalignments between the read and write heads at each respective track. One set is generated by the write head. The other set is generated by the write head while the read head is aligned with said one set. Thereafter, to write data on a selected track, the read head is first aligned with said one set of servo information and then data is written on said track with the write head. To read data on a selected track, the read head is aligned to said other set of servo information and then the data is read by said read head.

公开(公告)号：GB2275360B

公开(公告)日：1996-07-17

申请号：GB9401189

申请日：1994-01-21

Applicant: IBM

Inventor： CHEN MAO-MIN ,  GALLAGHER TIMOTHY JOSEPH ,  WANG PO-KANG

IPC: G01R33/09 ,  G11B5/03 ,  G11B5/39 ,  H01L43/08

Abstract: A magnetoresistive (MR) read transducer and method of fabricating same. A soft magnetic layer and an MR layer extend over a central active region and passive end regions of the transducer. A nonmagnetic spacer layer separates the soft magnetic film layer and MR layer and extends over the central active region and at least part of both passive end regions. An antiferromagnetic layer directly contacts the MR layer only in the end regions and produces an exchange bias field between the antiferromagnetic layer and the MR layer that is oriented at a preselected acute angle to the longitudinal direction of the transducer. This results in the MR layer being oriented at the preselected acute angle and the soft magnetic film layer in the passive end regions being transversely oriented by magnetostatic coupling to the MR layer. To fabricate the transducer, the antiferromagnetic layer is annealed in an external field above the Neel temperature to produce the canted exchange bias field. As a result of the canting, the magnetic moments of the central active region and the passive end regions are matched during a read operation.

公开(公告)号：DE69021315D1

公开(公告)日：1995-09-07

申请号：DE69021315

申请日：1990-09-28

Applicant: IBM

Inventor： KROUNBI MOHAMAD TOWFIK ,  VOEGELI OTTO ,  WANG PO-KANG

IPC: G11B5/39

公开(公告)号：DE68923539D1

公开(公告)日：1995-08-24

申请号：DE68923539

申请日：1989-12-18

Applicant: IBM

Inventor： KROUNBI MOHAMAD TOWFIK ,  VOEGELI OTTO ,  WANG PO-KANG

IPC: G11B5/39

Abstract: A magnetoresistive (MR) read transducer comprising an MR layer (11) having passive end regions (14) separated by a central active region (12). A longitudinal bias is produced by a thin film (16) of hard magnetic material in the end regions only, and the thin film of hard magnetic material is spaced from the MR layer by a nonmagnetic spacer layer (18) so that a magnetostatic longitudinal bias is produced of a level to maintain the passive end regions of the MR layer in a stable state.

公开(公告)号：DE69018382D1

公开(公告)日：1995-05-11

申请号：DE69018382

申请日：1990-11-07

Applicant: IBM

Inventor： BEST JOHN STEWART ,  WANG PO-KANG

IPC: G11B5/596 ,  G11B21/10

Abstract: A method of positioning separate read and write heads in a disk file compensates for misalignment of the heads when reading and writing data on the disk. Two sets of servo information are generated for each track on the disk. These sets are radially displaced with respect to each other by a distance equal to the respective misalignments between the read and write heads at each respective track. One set is generated by the write head. The other set is generated by the write head while the read head is aligned with said one set. Thereafter, to write data on a selected track, the read head is first aligned with said one set of servo information and then data is written on said track with the write head. To read data on a selected track, the read head is aligned to said other set of servo information and then the data is read by said read head.