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US5598308A
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Magnetoresistive sensor having multilayer thin film structure
Assignee: HGST Netherlands BV
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Filing: 1994-08-15
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Granted: 1997-01-28
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Expires: 2014-08-15
Abstract
Abstract A magnetoresistive (MR) sensor comprising a layered structure having at least one trilayer comprising a first and a second thin film ferromagnetic layers separated by and in interfacial contact with a third thin film non-metallic magnetic layer. A fourth thin film layer of material is within the first ferromagnetic layer, and the fourth layer has a thickness between a fraction of a monolayer and several monolayers and is located at predetermined distance from the interface between the first and third layers. A current flow is produced through the MR sensor and variations in resistivity of the MR sensor produced by rotation of the magnetization in one or both of the ferromagnetic layers is sensed as a function of the magnetic field being sensed.
Inventors
- 👤 Bernard Dieny
- 👤 Bruce A. Gurney
- 👤 Stuart S. P. Parkin
- 👤 Ian L. Sanders
- 👤 Virgil S. Speriosu
- 👤 Dennis R. Wilhoit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:45
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; B; B82; B82Y; B82Y10/00; B82Y25/00; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B2005/3996
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A magnetoresistive sensor comprising a first layer of ferromagnetic material and a second layer of ferromagnetic material, said first and second ferromagnetic layers separated by a spacer layer of non-magnetic material, each of said first and second ferromagnetic layers being in contact with an adjacent surface of said non-magnetic layer, an interface being formed therebetween, at least one of said first and second ferromagnetic layers including therein a thin layer of metallic material sandwiched within ,said ferromagnetic layer, said thin layer of metallic material spaced from said interface between said ferromagnetic layer and said spacer layer a distance x, said thin layer of metallic material forming a localized region within said ferromagnetic layer wherein the spin dependent scattering properties are different from the spin dependent scattering properties of said ferromagnetic material.
Claim 2
Dependent Claim
131 words
A magnetoresistive sensor comprising a first layer of ferromagnetic material and a second layer of ferromagnetic material, said first and second ferromagnetic layers separated by a spacer layer of non-magnetic material, each of said first and second ferromagnetic layers being in contact with an adjacent surface of said non-magnetic layer, an interface being formed therebetween, at least one of said first and second ferromagnetic layers including therein a thin layer of metallic material sandwiched within ,said ferromagnetic layer, said thin layer of metallic material spaced from said interface between said ferromagnetic layer and said spacer layer a distance x, said thin layer of metallic material forming a localized region within said ferromagnetic layer wherein the spin dependent scattering properties are different from the spin dependent scattering properties of said ferromagnetic material.
Claim 3
Dependent Claim
23 words
A magnetoresistive sensor as in claim 1 wherein said distance x is in a range from greater than 0 Angstroms to 17.5 Angstroms.
Claim 4
Dependent Claim
38 words
A magnetoresistive sensor as in claim 1 wherein each of said first and second ferromagnetic layers includes therein a thin layer of material spaced from the interface between said ferromagnetic layer and said spacer layer a distance x.
Claim 5
Dependent Claim
18 words
A magnetoresistive sensor as in claim 3 wherein said thin layer comprises a layer of a non-magnetic material.
Claim 6
Dependent Claim
18 words
A magnetoresistive sensor as in claim 3 wherein said thin layer comprises a layer of a magnetic material.
Claim 7
Dependent Claim
13 words
A magnetoresistive sensor as in claim 5 wherein said magnetic material comprises cobalt.
Claim 8
Dependent Claim
26 words
A magnetoresistive sensor as in claim 6 wherein said thin layer of cobalt has a thickness in the range of about 0.5 Angstroms to 20 Angstroms.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-28 | 2000-07-29 | 2001-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-28 | 2004-07-29 | 2005-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-28 | 2008-07-29 | 2009-01-28 | $7700.00 | Window Closed / Lapsed |