ANTIFERROMAGNETIC EXCHANGE COUPLING IN MAGNETORESISTIVE SPIN VALVE SENSORS

    公开(公告)号:MY136486A

    公开(公告)日:2008-10-31

    申请号:MYPI9301481

    申请日:1993-07-28

    Applicant: IBM

    Abstract: A MAGNETORESISTIVE READ SENSOR BASED ON THE SPIN VALVE EFFECT IN WHICH A COMPONENT OF THE READ ELEMENT RESISTANCE VARIES AS THE COSINE OF THE ANGLE BETWEEN THE MAGNETIZATION DIRECTIONS IN TWO MAGNETIC LAYERS IS DESCRIBED. THE SENSOR READ ELEMENT INCLUDES TWO ADJACENT FERROMAGNETIC LAYERS SEPARATED BY A NONMAGNETIC METALLIC LAYER. A LAYER OF ANTIFERROMAGNETIC MATERIAL IS FORMED OVER ONE OF THE FERROMAGNETIC LAYERS TO PROVIDE AN EXCHANGE BIAS FIELD WHICH FIXES OR ''PINS'' THE MAGNETIZATION DIRECTION IN THE ONE FERROMAGNETIC LAYER. AN INTERLAYER OF MAGNETICALLY SOFT MATERIAL IS DISPOSITED BETWEEN THE FERROMAGNETIC AND ANTIFERROMAGNETIC LAYERS SEPARATING THE FERROMAGNETIC LAYER FROM THE ANTIFERROMAGNETIC LAYER AND ENHANCING THE EXCHANGE COUPLING, PARTICULARLY IN THE INSTANCE WHERE THE FERROMAGNETIC MATERIAL IN IRON OR AN IRON ALLOY.

    12.
    发明专利
    未知

    公开(公告)号:DE69317178T2

    公开(公告)日:1998-10-29

    申请号:DE69317178

    申请日:1993-08-12

    Applicant: IBM

    Abstract: A magnetoresistive read sensor based on the spin valve effect in which a component of the read element resistance varies as the cosine of the angle between the magnetization directions in two adjacent magnetic layers is described. The sensor read element includes two adjacent ferromagnetic layers separated by a nonmagnetic metallic layer. A layer of antiferromagnetic material is formed over one of the ferromagnetic layers to provide an exchange bias field which fixes or "pins" the magnetization direction in the one ferromagnetic layer. An interlayer of magnetically soft material is deposited between the ferromagnetic and antiferromagnetic layers separating the ferromagnetic layer from the antiferromagnetic layer and enhancing the exchange coupling, particularly in the instance where the ferromagnetic material is iron or an iron alloy.

    13.
    发明专利
    未知

    公开(公告)号:DE69316708T2

    公开(公告)日:1998-08-06

    申请号:DE69316708

    申请日:1993-11-01

    Applicant: IBM

    Abstract: A magnetoresistive read sensor 30 based on the spin valve effect incorporates a multilayered, dual spin valve structure. The sensor read element includes first 31, second 35 and third 39 layers of ferromagnetic material separated from each other by layers of non-magnetic metallic material. The first and third layers of ferromagnetic material, i.e., the outer layers of the structure, have their magnetization orientation fixed, while the second, intermediate ferromagnetic layer is magnetically soft and has its magnetization oriented perpendicular to that of both the outer ferromagnetic layers in the absence of an applied magnetic field. In one preferred embodiment, the two outer ferromagnetic layers have their magnetizations fixed parallel to each other by exchange coupling with adjacent antiferromagnetic layers. In a second preferred embodiment, the directions or magnetization in the first and third layers of ferromagnetic material are aligned in an antiparallel orientation.

    14.
    发明专利
    未知

    公开(公告)号:DE69317178D1

    公开(公告)日:1998-04-09

    申请号:DE69317178

    申请日:1993-08-12

    Applicant: IBM

    Abstract: A magnetoresistive read sensor based on the spin valve effect in which a component of the read element resistance varies as the cosine of the angle between the magnetization directions in two adjacent magnetic layers is described. The sensor read element includes two adjacent ferromagnetic layers separated by a nonmagnetic metallic layer. A layer of antiferromagnetic material is formed over one of the ferromagnetic layers to provide an exchange bias field which fixes or "pins" the magnetization direction in the one ferromagnetic layer. An interlayer of magnetically soft material is deposited between the ferromagnetic and antiferromagnetic layers separating the ferromagnetic layer from the antiferromagnetic layer and enhancing the exchange coupling, particularly in the instance where the ferromagnetic material is iron or an iron alloy.

    Magnetoresistance sensor
    15.
    发明专利

    公开(公告)号:SG42845A1

    公开(公告)日:1997-10-17

    申请号:SG1996000076

    申请日:1993-11-01

    Applicant: IBM

    Abstract: A magnetoresistive read sensor 30 based on the spin valve effect incorporates a multilayered, dual spin valve structure. The sensor read element includes first 31, second 35 and third 39 layers of ferromagnetic material separated from each other by layers of non-magnetic metallic material. The first and third layers of ferromagnetic material, i.e., the outer layers of the structure, have their magnetization orientation fixed, while the second, intermediate ferromagnetic layer is magnetically soft and has its magnetization oriented perpendicular to that of both the outer ferromagnetic layers in the absence of an applied magnetic field. In one preferred embodiment, the two outer ferromagnetic layers have their magnetizations fixed parallel to each other by exchange coupling with adjacent antiferromagnetic layers. In a second preferred embodiment, the directions or magnetization in the first and third layers of ferromagnetic material are aligned in an antiparallel orientation.

    Magnetoresistive sensor
    16.
    发明专利

    公开(公告)号:SG42342A1

    公开(公告)日:1997-08-15

    申请号:SG1996001706

    申请日:1992-02-07

    Applicant: IBM

    Abstract: A magnetoresistive (MR) sensor comprising a layered structure formed on a substrate (11) includes a first (12) and a second (16) thin film layer (14) of magnetic material separated by a thin film layer of non-magnetic metallic material such as Cu, Au, or Ag, with at least one of the layers of ferromagnetic material formed of either cobalt or a cobalt alloy. The magnetization direction of the first ferromagnetic layer, at zero applied field, is set substantially perpendicular to the magnetization direction of the second ferromagnetic layer which is fixed in position. A current flow is produced through the sensor, and the variations in voltage across the MR sensor are sensed due to the changes in resistance produced by rotation of the magnetization in the front layer of ferromagnetic material as a function of the magnetic field being sensed.

    MAGNETORESISTIVE SENSOR BASED ON THE SPIN VALVE EFFECT

    公开(公告)号:CA2054580C

    公开(公告)日:1994-05-03

    申请号:CA2054580

    申请日:1991-10-31

    Applicant: IBM

    Abstract: MAGNETORESISTIVE SENSOR BASED ON THE SPIN VALVE EFFECT A magnetoresistive (MR) sensor comprising a first and a second thin film layer of a magnetic material separated by a thin film layer of a non-magnetic metallic material. The first ferromagnetic layer is magnetically soft. The magnetization direction of the first layer of magnetic material is set substantially perpendicular to the magnetization of the second layer of magnetic material at zero applied field, and the magnetization direction of the second layer of magnetic material is fixed. A current flow is produced through the MR sensor, and the variations in voltage across the MR sensor are sensed due to changes in resistance of the MR sensor produced by rotation of the magnetization in the first layer of magnetic material as a function of the magnetic field being sensed. The variation of the resistance with the angle between the magnetizations of the first and second layers of magnetic material has been defined as the spin valve (SV) effect. It is also shown that, by a suitable direction of the current with respect to the fixed magnetization, the (SV) magnetoresistance can be added constructively to the usual anisotropic magnetoresistance.

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