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公开(公告)号：DE69019485D1
公开(公告)日：1995-06-22
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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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
Inventor： BAUMGART PETER MICHAEL , DIENY BERNARD , GURNEY BRUCE ALVIN , SPERIOSU VIRGIL SIMON , WILHOIT DENNIS RICHARD
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.
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公开(公告)号：DE69534013T2
公开(公告)日：2006-05-04
申请号：DE69534013
申请日：1995-10-27
Applicant: IBM
Abstract: A magnetic field sensor (10) uses four individual magnetoresistive spin valve elements (A,B,C,D) electrically connected in a bridge circuit. The spin valve elements (A,B,C,D) are lithographically formed on the same substrate with their free layers (36) 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 (39) to be antiparallel to the direction of magnetization of the other two pinned layers (39). The bridge circuit (10) output voltage is responsive to an external magnetic field (4) in the plane of the sensor (10). By appropriate fixing of the direction of magnetization of the pinned layers (39) during sensor (10) fabrication, and appropriate connection to the input (20,22) and output leads (24,26), the bridge circuit output voltage is a measure of either the magnetic field or field gradient.
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公开(公告)号：DE69534314T2
公开(公告)日：2006-04-20
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：DE69430964T2
公开(公告)日：2003-02-13
申请号：DE69430964
申请日：1994-01-11
Applicant: IBM
Inventor： GURNEY BRUCE ALVIN , HEIM DAVID EUGENE , LEFAKIS HARALAMBOS , NEED III OMAR U , 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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Patent Agency Ranking
公开(公告)号：DE69611326T2
公开(公告)日：2001-05-31
申请号：DE69611326
申请日：1996-06-13
Applicant: IBM
Inventor： FONTANA JR , GURNEY BRUCE ALVIN , LIN TSANN , SPERIOSU VIRGIL SIMON , TSANG CHING HWA , WILHOIT DENNIS RICHARD
Abstract: A spin valve magnetoresistive (SVMR) sensor uses a laminated antiparallel (AP) pinned layer 70 in combination with an improved antiferromagnetic (AF) exchange biasing layer 57. The pinned layer comprises two ferromagnetic films 72, 74 separated by a nonmagnetic coupling film 73 such that the magnetizations of the two ferromagnetic films are strongly coupled together antiferromagnetically in an antiparallel orientation. This laminated AP pinned layer is magnetically rigid in the small field excitations required to rotate the SVMR sensor's free layer. When the magnetic moments of the two ferromagnetic layers in this AP pinned layer are nearly the same, the net magnetic moment of the pinned layer is small. However, the exchange field is correspondingly large because it is inversely proportional to the net magnetic moment. The laminated AP pinned layer has its magnetization fixed or pinned by an AF material that is highly corrosion resistant but that has an exchange anisotropy too low to be usable in conventional SVMR sensors. In the preferred embodiment the AF layer is nickel-oxide and is formed on one of the magnetoresistive (MR) shields that serves as the substrate 45. Thus the AF material also serves as the insulating MR gap material. The location of the AF layer and the laminated AP-pinned layer to which it is exchange coupled on the bottom of the SVMR sensor allows for improved longitudinal biasing of the free layer when the SVMR sensor is fabricated.
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公开(公告)号：DE69611326D1
公开(公告)日：2001-02-01
申请号：DE69611326
申请日：1996-06-13
Applicant: IBM
Inventor： FONTANA JR , GURNEY BRUCE ALVIN , LIN TSANN , SPERIOSU VIRGIL SIMON , TSANG CHING HWA , WILHOIT DENNIS RICHARD
Abstract: A spin valve magnetoresistive (SVMR) sensor uses a laminated antiparallel (AP) pinned layer 70 in combination with an improved antiferromagnetic (AF) exchange biasing layer 57. The pinned layer comprises two ferromagnetic films 72, 74 separated by a nonmagnetic coupling film 73 such that the magnetizations of the two ferromagnetic films are strongly coupled together antiferromagnetically in an antiparallel orientation. This laminated AP pinned layer is magnetically rigid in the small field excitations required to rotate the SVMR sensor's free layer. When the magnetic moments of the two ferromagnetic layers in this AP pinned layer are nearly the same, the net magnetic moment of the pinned layer is small. However, the exchange field is correspondingly large because it is inversely proportional to the net magnetic moment. The laminated AP pinned layer has its magnetization fixed or pinned by an AF material that is highly corrosion resistant but that has an exchange anisotropy too low to be usable in conventional SVMR sensors. In the preferred embodiment the AF layer is nickel-oxide and is formed on one of the magnetoresistive (MR) shields that serves as the substrate 45. Thus the AF material also serves as the insulating MR gap material. The location of the AF layer and the laminated AP-pinned layer to which it is exchange coupled on the bottom of the SVMR sensor allows for improved longitudinal biasing of the free layer when the SVMR sensor is fabricated.
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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
Inventor： BAUMGART PETER MICHAEL , DIENY BERNARD , GURNEY BRUCE ALVIN , SPERIOSU VIRGIL SIMON , WILHOIT DENIS RICHARD
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.
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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
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：DE69317178D1
公开(公告)日：1998-04-09
申请号：DE69317178
申请日：1993-08-12
Applicant: IBM
Inventor： BAUMGART PETER MICHAEL , DIENY BERNARD , GURNEY BRUCE ALVIN , SPERIOSU VIRGIL SIMON , WILHOIT DENIS RICHARD
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.
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