US4236230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bistable magnetostrictive device
Assignee: International Business Machines Corp
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Filing: 1977-12-19
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Granted: 1980-11-25
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Expires: 1997-12-19
Abstract
Abstract A device includes a core, such as a wire or cylinder of a solid material such as nonmagnetic metal, coated with a film of a material having a high degree of magnetostriction and a uniaxial helical magnetic anisotropy at an oblique angle to the longitudinal axis of the core. The device has the characteristic of being magnetically bistable and of providing a large magnetic pulse as it changes to one of its stable states in response to passage of a magnetic field by it. To achieve a helical magnetic anisotropy, the magnetostrictive film can be applied to a nonmagnetic wire by plating the wire while it is under torsion, twisting a plated wire after plating, or by applying an electric current and a magnetic field to the wire as the film is being plated or annealed.
Inventors
- 👤 David A. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:28
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/02; G11C11/12; H; H10; H10N; H10N35/00; H10N35/01
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
118 words
An elongated unitary magnetic device comprising first and second portions having dissimilar chemical compositions, at least said first portion being magnetostrictive and being capable of retaining net magnetization after being subjected to a magnetic field, the net coercivity of said first portion being substantially greater than the net coercivity of the second portion, said first and said second portions being separated along an interface of different composition providing a magnetic domain interface when said first portion has a net magnetization in a first direction and said second portion has a net magnetization substantially opposite from said first direction, and said first portion having a helical magnetic anisotropy about an axis along the overall length of said elongated device.
Claim 2
Dependent Claim
118 words
An elongated unitary magnetic device comprising first and second portions having dissimilar chemical compositions, at least said first portion being magnetostrictive and being capable of retaining net magnetization after being subjected to a magnetic field, the net coercivity of said first portion being substantially greater than the net coercivity of the second portion, said first and said second portions being separated along an interface of different composition providing a magnetic domain interface when said first portion has a net magnetization in a first direction and said second portion has a net magnetization substantially opposite from said first direction, and said first portion having a helical magnetic anisotropy about an axis along the overall length of said elongated device.
Claim 3
Dependent Claim
14 words
A device in accordance with claim 1 wherein said second portion comprises a wire.
Claim 4
Dependent Claim
14 words
A device in accordance with claim 1 wherein said second portion comprises a ribbon.
Claim 5
Dependent Claim
16 words
A device in accordance with claim 1 wherein said second portion comprises a thin film stripe.
Claim 6
Dependent Claim
14 words
A device in accordance with claim 1 wherein said second portion comprises a fiber.
Claim 7
Dependent Claim
110 words
An elongated magnetostrictive device in accordance with claim 1, said second portion comprising a core composed of an elongated body, said first portion comprising a thin film coating on the exterior of said core having a high degree of magnetostriction, said thin film coating having a uniaxial helical, magnetic anisotropy about the circumference of said core within said coating and about the longitudinal axis of said elongated device at an angle of about 45° relative to said longitudinal axis, and said helical magnetic anisotropy having been provided by twisting said core and said coating beyond the elastic limit of said coating subsequent to deposition of said coating onto said body.
Claim 8
Dependent Claim
15 words
A device in accordance with claim 6 wherein said core comprises a hollow tubular structure.
Claim 9
Dependent Claim
115 words
An elongated magnetostrictive device in accordance with claim 1, said second portion comprising a core composed of an elongated body, said first portion comprising a thin film coating on the exterior of said core having a high degree of magnetostriction, said thin film coating having a uniaxial helical, magnetic anisotropy about the circumference of said core within said coating and about the longitudinal axis of said elongated device at an angle of about 45° relative to said longitudinal axis, and said helical anisotropy having been produced by maintaining said core under torsional strain during deposition of said coating on said core and by releasing said core from torsional strain subsequent to deposition of said coating.
Claim 10
Dependent Claim
15 words
A device in accordance with claim 8 wherein said core comprises a hollow tubular structure.
Claim 11
Dependent Claim
13 words
A device in accordance with claim 8 wherein said core comprises a wire.
Claim 12
Dependent Claim
13 words
A device in accordance with claim 8 wherein said core comprises a ribbon.
Claim 13
Dependent Claim
13 words
A device in accordance with claim 8 wherein said core comprises a fiber.
Claim 14
Dependent Claim
96 words
An elongated magnetostrictive device in accordance with claim 1, said second portion comprising a core composed of an elongated body, said first portion comprising a thin film coating on the exterior of said core having a high degree of magnetostriction, said thin film coating having a uniaxial helical, magnetic anisotropy about the circumference of said core within said coating and about the longitudinal axis of said elongated device at an angle of about 45° relative to said longitudinal axis, and said helical magnetic anisotropy having been produced by annealing said device in a helica magnetic field.
Claim 15
Dependent Claim
15 words
A device in accordance with claim 13 wherein said core comprises a hollow tubular structure.
Claim 16
Dependent Claim
13 words
A device in accordance with claim 13 wherein said core comprises a wire.
Claim 17
Dependent Claim
13 words
A device in accordance with claim 13 wherein said core comprises a ribbon.
Claim 18
Dependent Claim
13 words
A device in accordance with claim 13 wherein said core comprises a fiber.
Claim 19
Dependent Claim
13 words
A device in accordance with claim 13 wherein said core comprises a fiber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |