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11.发明专利
公开(公告)号：SG42851A1
公开(公告)日：1997-10-17
申请号：SG1996000141
申请日：1994-01-11
Applicant: IBM
Inventor： GURNEY BRUCE ALVIN , HEIM DAVID EUGENE , LEFAKIS HARALAMBOS , NEED OMAR U III , SPERIOSU VIRGIL SIMON , WILHOIT DENNIS RICHARD
Abstract: A magnetoresistive read sensor based on the spin valve effect is described, 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. The sensor read element includes two adjacent ferromagnetic layers separated by a nonmagnetic metallic layer. A layer of nonmagnetic electrically conductive material is deposited adjacent to and in contact with at least one of the ferromagnetic layers (referred to as a filter layer) to form a back or conduction layer which provides a low resistance path for conduction electrons transmitted through the adjacent filter layer. The thickness of the filter layer is selected such that it effectively blocks conduction electrons having spins antiparallel to the direction of magnetization in the filter layer while allowing conduction electrons with parallel spins to be transmitted through the layer into the adjacent back layer. The magnetization of the filter layer is free to rotate in response to an applied magnetic field thereby effectively varying the electrically resistance to conduction electrons in the back/filter layer. The thickness of the back layer is selected to optimize the sensor parameters being measured and is in a range of about 4.0A to 1000A.
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公开(公告)号：CA2158304A1
公开(公告)日：1996-05-05
申请号：CA2158304
申请日：1995-09-14
Applicant: IBM
Inventor： DOVEK MORIS MUSA , FONTANA ROBERT EDWARD JR , SPERIOSU VIRGIL SIMON , SPONG JACQUELIN KETNER
Abstract: A magnetic field sensor uses four individual magnetoresistive spin valve elements electrically connected in a bridge circuit. The spin valve elements are lithographically formed on the same substrate with their free layers having their magnetization axes parallel to one another. An electrically conductive fixing layer is formed on the substrate but is insulated from the spin valve elements. The application of current through the fixing conductor during fabrication of the field sensor fixes the direction of magnetization of two of the pinned layers to be antiparallel to the direction of magnetization of the other two pinned layers. The bridge circuit output voltage is responsive to an external magnetic field in the plane of the sensor. By appropriate fixing of the direction of magnetization of the pinned layers during sensor fabrication, and appropriate connection to the input and output leads, the bridge circuit output voltage is a measure of either the magnetic field or field gradient. The fixing conductor, or a separate current strap formed on the substrate, can be used to pass an unknown current over the sensor, in which case the bridge circuit output voltage is a measure of the unknown current.
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公开(公告)号：DE69534314D1
公开(公告)日：2005-08-25
申请号：DE69534314
申请日：1995-05-02
Applicant: IBM
Inventor： COFFEY KEVIN ROBERT , GURNEY BRUCE ALVIN , HEIM DAVID EUGENE , LEFAKIS HARALAMBOS , MAURI DANIELE , SPERIOSU VIRGIL SIMON , WILHOIT DENNIS RICHARD
Abstract: An SVMR sensor (60) having a self-pinned laminated layer (70) with at least two ferromagnetic films (72,74) antiferromagnetically coupled to one another across a thin antiferromagnetically (AF) coupling film (73). Since the two ferromagnetic films (72,74) in this laminated layer (70) have their magnetic moments aligned antiparallel, their two magnetic moments can be made to essentially cancel by making the two ferromagnetic films (72,74) of substantially the same thickness. The magnetic field energy generated by the signal field acting on this laminated layer (70) will be significantly less than the effective anisotropy energy of the laminated layer (70). As a result, the laminated layer (70) will not rotate in the presence of the signal field, but will be "self-pinned". A hard-bias or exchange bias layer in not needed, also eliminating the need for Ni-Mn and its associated high-temperature process.
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公开(公告)号：DE69132027T2
公开(公告)日：2000-09-14
申请号：DE69132027
申请日：1991-12-09
Applicant: IBM
Inventor： DIENY BERNARD , GURNEY BRUCE ALVIN , LAMBERT STEVEN EUGENE , MAURI DANIELE , PARKIN STUART STEPHEN PAPWORTH , SPERIOSU VIRGIL SIMON , WILHOIT DENNIS RICHARD
Abstract: A magnetoresistive (MR) sensor is disclosed which comprises 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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公开(公告)号：DE69326308T2
公开(公告)日：2000-04-20
申请号：DE69326308
申请日：1993-11-15
Applicant: IBM
Inventor： CAIN WILLIAM CHARLES , DIENY BERNARD , FONTANA ROBERT EDWARD , SPERIOSU VIRGIL SIMON
Abstract: A magnetoresistive 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 non-magnetic metallic layer, the magnetic easy axis of each of the ferromagnetic layers being aligned along the longitudinal axis of the ferromagnetic layers and perpendicular to the trackwidth of an adjacent magnetic storage medium. The sense current flowing in the sensor element generates a bias field which sets the direction of magnetization in each ferromagnetic layer at an equal, but opposite, angle theta with respect to the magnetic easy axis thus providing an angular separation of 2 theta in the absence of an applied magnetic signal. The magnetizations of both ferromagnetic layers are responsive to an applied magnetic field to change their angular separation by an amount 2 delta theta .
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Patent Agency Ranking
公开(公告)号：DE69316708D1
公开(公告)日：1998-03-05
申请号：DE69316708
申请日：1993-11-01
Applicant: IBM
Inventor： BAUMGART PETER MICHAEL , DIENY BERNARD , GURNEY BRUCE ALVIN , NOZIERES JEAN-PIERRE , SPERIOSU VIRGIL SIMON , WILHOIT DENNIS RICHARD
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.
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公开(公告)号：SG42330A1
公开(公告)日：1997-08-15
申请号：SG1996000779
申请日：1993-11-15
Applicant: IBM
Abstract: A magnetoresistive 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 non-magnetic metallic layer, the magnetic easy axis of each of the ferromagnetic layers being aligned along the longitudinal axis of the ferromagnetic layers and perpendicular to the trackwidth of an adjacent magnetic storage medium. The sense current flowing in the sensor element generates a bias field which sets the direction of magnetization in each ferromagnetic layer at an equal, but opposite, angle theta with respect to the magnetic easy axis thus providing an angular separation of 2 theta in the absence of an applied magnetic signal. The magnetizations of both ferromagnetic layers are responsive to an applied magnetic field to change their angular separation by an amount 2 delta theta .
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公开(公告)号：DE69216868D1
公开(公告)日：1997-03-06
申请号：DE69216868
申请日：1992-02-07
Applicant: IBM
Inventor： DIENY BERNARD , CURNEY BRUCE ALVIN , METIN SERHAT , PARKIN STUART STEPHEN PAPWORTH , SPERIOSU VIRGIL SIMON
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.
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公开(公告)号：SG30327A1
公开(公告)日：1996-06-01
申请号：SG1995000170
申请日：1995-03-27
Applicant: IBM
Inventor： GURNEY BRUCE ALVIN , MAURI DANIEL , HEIM DAVID EUGENE , WILHOIT DENNIS RICHARD , LEFAKIS HARALAMBOS , COFFEY KEVIN ROBERT , SPERIOSU VIRGIL SIMON
IPC: G11B5/39
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公开(公告)号：DE69019485T2
公开(公告)日：1996-01-25
申请号：DE69019485
申请日：1990-10-30
Applicant: IBM
Inventor： PARKIN STUART , ROCHE KEVIN PATRICK , SPERIOSU VIRGIL SIMON
Abstract: An improved thin'film magnetoresistive (MR) sensor uses an alloy comprising Fe(1-x)Mnx where x is within the range of 0.3 to 0.4, as an antiferromagnetic layer to provide longitudinal exchange bias in the ferromagnetic MR layer. In a specific embodiment the exchange bias is at a high level and is independent of thickness of the antiferromagnetic layer over a wide range.
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