EP0216062A1
Expired / Lapsed
EP
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Magnetoresistive read transducer assembly
Assignee: International Business Machines Corp
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Filing: 1986-07-22
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Granted: —
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Expires: 2006-07-22
Abstract
Abstract A magnetoresistive (MR) read transducer assembly comprises a thin film MR layer (10) which is longitudinally biased only in the end regions (12) by exchange bias developed by a thin film of antiferromagnetic material (16) that is deposited in direct contact with the MR layer in the end regions. The longitudinal bias is of a level sufficient to maintain the end regions of the MR layer in a single domain state and thereby induce a single domain state in the central region (14) of the MR layer. Transverse bias is produced within the central region of the MR layer of a level sufficient to maintain that region of the MR layer in a linear response mode. Spaced conductive elements (18,20) are connected to the MR layer within the central region to define a detection region so that sensing means connected to the conductive elements can determine the resistance changes in the detection region of the MR layer resulting from the magnetic fields intercepted by the MR layer.
Inventors
- 👤 Ching Hwa Tsang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 20:02
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; H; H10; H10N; H10N50/00; H10N50/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
A magnetoresistive read transducer assembly comprising: a thin film magnetoresistive layer (10) means (16) for producing a longitudinal bias in only the end regions (12) of the magnetoresistive layer, the longitudinal bias being of a level sufficient to maintain the end regions of the magnetoresistive layer in a single domain state, means (18,20,21) for producing a transverse bias in at least a part of the central region (14) between said two end regions of said magnetoresistive layer, the transverse bias being of a level sufficient to maintain said part of the central region of the magnetoresistive layer in a linear response mode; and conductive means (18,20) connected to said magnetoresistive layer within said central region to define a detection region so that resistance changes in the detection region produced by magnetic fields which are intercepted by the magnetoresistive layer can be detected.
Claim 2
Dependent Claim
142 words
A magnetoresistive read transducer assembly comprising: a thin film magnetoresistive layer (10) means (16) for producing a longitudinal bias in only the end regions (12) of the magnetoresistive layer, the longitudinal bias being of a level sufficient to maintain the end regions of the magnetoresistive layer in a single domain state, means (18,20,21) for producing a transverse bias in at least a part of the central region (14) between said two end regions of said magnetoresistive layer, the transverse bias being of a level sufficient to maintain said part of the central region of the magnetoresistive layer in a linear response mode; and conductive means (18,20) connected to said magnetoresistive layer within said central region to define a detection region so that resistance changes in the detection region produced by magnetic fields which are intercepted by the magnetoresistive layer can be detected.
Claim 3
Dependent Claim
18 words
A magnetoresistive read transducer assembly as claimed in claim 1, wherein said magnetoresistive layer is composed of NiFe.
Claim 4
Dependent Claim
28 words
A magnetoresistive read transducer assembly as claimed in claim 1 or claim 2, wherein said magnetoresistive layer has a thickness in the range of 20 to 50 nm.
Claim 5
Dependent Claim
55 words
A magnetoresistive read transducer as claimed in any preceding claim, in which the means for producing a longitudinal bias in only the end regions of the magnetoresistive layer comprises a thin film of antiferromagnetic material in direct contact with only said end regions of said magnetoresistive layer to produce said longitudinal bias by exchange biasing.
Claim 6
Dependent Claim
21 words
A magnetoresistive read transducer assembly as claimed in claim 4, wherein said thin film of antiferromagnetic material is composed of MnFe.
Claim 7
Dependent Claim
31 words
A magnetoresistive read transducer assembly as claimed in claim 4 or claim 5, wherein said thin film of antiferromagnetic material has a thickness in the range of 10 to 50 nm.
Claim 8
Dependent Claim
33 words
A magnetoresistive read transducer assembly as claimed in any preceding claim, wherein said conductive means comprises spaced conductive elements, and said detection region is defined by the inner edges of said conductive elements.
Claim 9
Dependent Claim
49 words
A magneticoresistive read transducer as claimed in any preceding claim, wherein the central region of said magnetoresistive layer which is not longitudinally biased, said detection region, and said at least a part of said central region in which a transverse bias is produced, are of substantially the same size.
Claim 10
Dependent Claim
91 words
A magnetoresistive read transducer assembly as claimed in any preceding claim, further comprising: a thin film of soft magnetic material disposed parallel to but spaced from the magnetoresistive layer; and means for supplying a bias current to said conductive means to magnetically bias said magnetoresistive layer with transverse bias of a level sufficient to maintain said magnetoresistive layer in a high sensitivity condition whereby signal sensing means connected to said conductive means can determine the resistance changes in said magnetoresistive layer as a function of the fields which are intercepted thereby.
Claim 11
Dependent Claim
22 words
A magnetoresistive read transducer assembly as claimed in claim 9 wherein said thin film of soft magnetic material is composed of NiFeRh.
Claim 12
Dependent Claim
27 words
A magnetoresistive read transducer assembly as claimed in Claim 9 or Claim 10, wherein said thin film of soft magnetic material is thinner than said magnetoresistive layer.
Claim 13
Dependent Claim
15 words
A magnetoresistive read transducer assembly as claimed in any preceding claim, disposed between magnetic shields.
References Cited (Backward Citations)
US4103315A
Cited
EP0152000A2
Cited
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