EP0334480A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetoresistive read transducer and a method for making it
Assignee: International Business Machines Corp
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Filing: 1989-02-16
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Granted: —
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Expires: 2009-02-16
Abstract
Abstract A magnetoresistive (MR) read transducer comprising an antiferromagnetic layer (14) in direct contact with an MR layer (12) is subjected to a thermal annealing process so that a ternary antiferromagnetic alloy is formed at the interface by diffusion. The ternary antiferromagnetic alloy has a high value of exchange bias which is less temperature sensitive. In a specific embodiment in which the MR layer is NiFe and the antiferromagnetic layer is FeMn, the ternary alloy formed by heating the structure to a temperature within the range of 260 DEG C to 350 DEG C for 50 to 20 hours has a room temperature exchange bias field with NiFe of about 0.65 Amp/metre (50 Oersted) and an ordering temperature which exceeds 300 DEG C.
Inventors
- 👤 James Kent Howard
- 👤 Michael Folsom Toney
- 👤 Ching Hwa Tsang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 23:41
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/399; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034; Y10T29/49036; Y10T29/49043; Y10T428/00; Y10T428/11; Y10T428/1107; Y10T428/1121; Y10T428/12; Y10T428/12465
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
67 words
A magnetoresistive read transducer assembly comprising a thin magnetoresistive layer (12) of ferromagnetic material and a thin layer (14) of antiferromagnetic material in direct contact with the magnetoresistive layer; the assembly being characterised by further comprising a thermally formed ternary antiferromagnetic material at the interface between said magnetoresistive layer and said layer of antiferromagnetic material, said ternary antiferromagnetic material exhibiting an ordering temperature exceeding 300 degrees centigrade.
Claim 2
Dependent Claim
67 words
A magnetoresistive read transducer assembly comprising a thin magnetoresistive layer (12) of ferromagnetic material and a thin layer (14) of antiferromagnetic material in direct contact with the magnetoresistive layer; the assembly being characterised by further comprising a thermally formed ternary antiferromagnetic material at the interface between said magnetoresistive layer and said layer of antiferromagnetic material, said ternary antiferromagnetic material exhibiting an ordering temperature exceeding 300 degrees centigrade.
Claim 3
Dependent Claim
32 words
A magnetoresistive read transducer assembly as claimed in claim 1, wherein said magnetoresistive layer comprises an alloy of nickel and iron and said antiferromagnetic layer comprises an alloy of iron and manganese.
Claim 4
Dependent Claim
23 words
A magnetoresistive read transducer assembly as claimed in claim 2, wherein said ternary antiferromagnetic material is an alloy comprising nickel, iron and manganese.
Claim 5
Dependent Claim
19 words
A magnetoresistive read transducer assembly as claimed in claim 3, wherein said ternary antiferromagnetic alloy comprises Ni₄₀ Mn₄₀ Fe₂₀.
Claim 6
Independent Claim
98 words
A method for making a magnetoresistive read transducer assembly comprising the steps of: depositing a thin magnetoresistive layer of ferromagnetic material; depositing a thin layer of antiferromagnetic material in direct contact with the magnetoresistive layer; and heating said layered structure to a temperature within a predetermined range for a predetermined time to form a ternary antiferromagnetic material at the interface between said magnetoresistive layer and said layer of antiferromagnetic material whereby said ternary antiferromagnetic material produces a high exchange bias field with said magnetoresistive layer and said ternary antiferromagnetic material exhibits an ordering temperature exceeding 300 degrees centigrade.
Claim 7
Independent Claim
98 words
A method for making a magnetoresistive read transducer assembly comprising the steps of: depositing a thin magnetoresistive layer of ferromagnetic material; depositing a thin layer of antiferromagnetic material in direct contact with the magnetoresistive layer; and heating said layered structure to a temperature within a predetermined range for a predetermined time to form a ternary antiferromagnetic material at the interface between said magnetoresistive layer and said layer of antiferromagnetic material whereby said ternary antiferromagnetic material produces a high exchange bias field with said magnetoresistive layer and said ternary antiferromagnetic material exhibits an ordering temperature exceeding 300 degrees centigrade.
Claim 8
Dependent Claim
29 words
A method as claimed in claim 5 wherein said magnetoresistive layer comprises an alloy of nickel and iron and said antiferromagnetic layer comprises an alloy of iron and manganese.
Claim 9
Dependent Claim
39 words
A method as claimed in claim 5 or claim 6, wherein said heating step is conducted at a temperature within the range of 260 to 350 degrees centigrade for a time within the range of 20 to 50 hours.
Claim 10
Dependent Claim
20 words
A method as claimed in claim 7, wherein the ternary antiferromagnetic material is an alloy comprising nickel, iron and manganese.
Claim 11
Dependent Claim
14 words
A method as claimed in claim 8, wherein the ternary antiferromagnetic alloy comprises Ni₄₀Mn₄₀Fe₂₀.
References Cited (Backward Citations)
No citation records indexed.
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