EP0432890A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetoresistive sensor
Assignee: International Business Machines Corp
•
Filing: 1990-10-30
•
Granted: —
•
Expires: 2010-10-30
Abstract
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.
Inventors
- 👤 Stuart Stephen Papworth Parkin
- 👤 Kevin Patrick Roche
- 👤 Virgil Simon Speriosu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 19:28
CPC Classifications
B; B82; B82Y; B82Y25/00; G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3929; G11B5/3932; G11B5/399
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
54 words
A magnetoresistive sensor having an antiferromagnetic layer in direct contact with a magnetoresistive ferromagnetic layer for inducing a longitudinal bias in the ferromagnetic layer, characterised in that said antiferromagnetic layer comprises an alloy of manganese (Mn) and iron (Fe), Fe (1-x) Mn x , where x is in the range of 0.3 to 0.4.
Claim 2
Dependent Claim
54 words
A magnetoresistive sensor having an antiferromagnetic layer in direct contact with a magnetoresistive ferromagnetic layer for inducing a longitudinal bias in the ferromagnetic layer, characterised in that said antiferromagnetic layer comprises an alloy of manganese (Mn) and iron (Fe), Fe (1-x) Mn x , where x is in the range of 0.3 to 0.4.
Claim 3
Dependent Claim
17 words
The sensor according to claim 1 wherein said ferromagnetic layer is an alloy comprising nickel and iron.
Claim 4
Dependent Claim
18 words
A sensor as claimed in Claim 2 wherein said alloy comprises about 80% nickel and about 20% iron.
Claim 5
Dependent Claim
35 words
A sensor as claimed in any of Claims 1, 2 or 3 further comprising an auxiliary layer in direct contact with said antiferromagnetic layer, said auxiliary layer comprising a material having a face-centred cubic structure.
Claim 6
Dependent Claim
13 words
A sensor as claimed in Claim 4 wherein said auxiliary layer comprises copper.
Claim 7
Dependent Claim
67 words
A sensor as claimed in any of the preceding claims further comprising a second layer of antiferromagnetic material in direct contact with said layer of ferromagnetic material for inducing a further bias in said magnetoresistive ferromagnetic layer, said second layer of antiferromagnetic material comprising an alloy of manganese (Mn) and iron (Fe), Fe (1-x) Mn x , where x is within the range of 0.3 to 0.4.
Claim 8
Dependent Claim
35 words
A sensor as claimed in any of the preceding claims further comprising means for producing a transverse bias in said magnetoresistive ferromagnetic layer whereby changes in the resistance of said ferromagnetic layer can be sensed.
Claim 9
Dependent Claim
21 words
A magnetic storage apparatus having a read head including a magnetoresistive sensor as claimed in any of Claims 1 to 7.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.