US3736579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circular magnetic domain devices
Assignee: Plessey Handel und Investments AG
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Filing: 1972-02-02
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Granted: 1973-05-29
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Expires: 1992-02-02
Abstract
Abstract A circular magnetic domain device which includes a layer of uniaxial magnetic material formed on or in a surface of a magnetic member having at least one easy magnetization direction substantially parallel to the said surface thereof, the layer material having a single unique easy magnetization direction substantially normal to the said surface. A first pattern of a soft magnetic material is interposed between the uniaxial magnetic layer and the magnetic member, and a pattern of an electrically conductive material is formed on the upper surface of the uniaxial magnetic layer. The magnetic member can be formed on the surface of a non-magnetic substrate, and a second soft magnetic pattern can be formed on the upper surface of the uniaxial magnetic layer. The second soft magnetic pattern can be complimentary to, and in register with, the first pattern in order to obtain higher propagation rates for the circular magnetic domains.
Inventors
- 👤 A Marsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:48
CPC Classifications
H; H01; H01F; H01F10/00; G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0858; H01F10/08; H01F10/10; H01F10/18; H01F10/20; H01F10/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
A circular magnetic domain device including a layer of uniaxial magnetic material formed on or in a surface of a magnetic member having at least one easy magnetization direction substantially parallel to the said surface thereof, the layer material having a single unique easy magnetization direction substantially normal to the said surface; a first pattern of a soft magnetic material interposed between the uniaxial magnetic layer and the magnetic member; and a pattern of an electrically conductive material formed on the upper surface of the uniaxial magnetic layer.
Claim 2
Dependent Claim
88 words
A circular magnetic domain device including a layer of uniaxial magnetic material formed on or in a surface of a magnetic member having at least one easy magnetization direction substantially parallel to the said surface thereof, the layer material having a single unique easy magnetization direction substantially normal to the said surface; a first pattern of a soft magnetic material interposed between the uniaxial magnetic layer and the magnetic member; and a pattern of an electrically conductive material formed on the upper surface of the uniaxial magnetic layer.
Claim 3
Dependent Claim
30 words
A circular magnetic domain device as claimed in claim 1 which includes a second pattern of a soft magnetic material formed on the upper surface of the uniaxial magnetic layer.
Claim 4
Dependent Claim
24 words
A circular magnetic domain device as claimed in claim 2 wherein the second pattern is complimentary to, and in register with, the first pattern.
Claim 5
Dependent Claim
20 words
A circular magnetic domain device as claimed in claim 1 wherein the uniaxial magnetic layer is a single crystal layer.
Claim 6
Dependent Claim
54 words
A circular magnetic domain device as claimed in claim 4 wherein the uniaxial magnetic layer material or both the layer material and the material of the magnetic member, is a garnet structure with a formula R3(Fe,M)5O12, where R is a single or a mixture of rare earth ions, and M is a non-magnetic ion.
Claim 7
Dependent Claim
32 words
A circular magnetic domain device as claimed in claim 5 wherein the rare earth ion is yttrium, and wherein the non-magnetic ion is taken from the group consisting of aluminium and gallium.
Claim 8
Dependent Claim
29 words
A circular magnetic domain device as claimed in claim 4 wherein the material of the magnetic member is Y3Fe5 xGaxO12 where x is in the range 0 to 1.0.
Claim 9
Dependent Claim
47 words
A circular magnetic domain device as claimed in claim 4 wherein the uniaxial magnetic layer material is a magneto-plumbite structure with a formula (AB)12O19 where A is a combination of barium, calcium, lead and strontium, and B is a combination of iron, aluminium, gallium, cobalt and titanium.
Claim 10
Dependent Claim
23 words
A circular magnetic domain device as claimed in claim 1 wherein the magnetic member is formed on the surface of a non-magnetic substrate.
Claim 11
Dependent Claim
28 words
A circular magnetic domain device as claimed in claim 9 wherein the substrate material is taken from the group consisting of gallium and an aluminium rich non-magnetic material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |