US3845477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling magnetization in garnet material and devices so produced
Assignee: AT&T Inc
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Filing: 1972-11-24
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Granted: 1974-10-29
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Expires: 1992-11-24
Abstract
Abstract Magnetization barriers for a variety of magnetic garnets containing partial non-magnetic substitutional ions replacing iron are altered by annealing. A relatively large order change in magnetization is effected under an intimately contacting layer of silicon which may cover the entirety of a surface or which may define a particular desired pattern. Magnetization changes, either increased or decreased, of the order of 30 percent or greater, may result from annealing for periods of the order of a few minutes within the temperature range of from about 500* to 800* C. Resulting ''''tailored'''' material may be utilized in magnetic switches or memories.
Inventors
- 👤 R Wolfe
- 👤 R Craw
- 👤 H Levinstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:22
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F10/20; H01F10/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
143 words
METHOD FOR ALTERING A MAGNETIC PROPERTY OF A BODY OF AN IRON-CONTAINING COMPOSITION OF THE GARNET STRUCTURE, SUCH COMPOSITION CONTAINING AT LEAST 5 CATION PERCENT OF A SUBSTITUTIONAL ION OTHER THAN IRON IN THE TETRAHEDRAL AND OCTAHEDRAL CRYSTALLOGRAPHIC SITES BASED ON THE TOTAL NUMBER OF CATIONS IN SUCH SITES, SAID METHOD COMPRISING HEATING OF SAID BODY, CHARACTERIZED IN THAT AT LEAST A PORTION OF THE SAID BODY IS IN INTIMATE CONTACT WITH ELEMENTAL SILICON DURING AT LEAST A PORTION OF THE SAID HEATING, IN THAT HEATING IS CARRIED OUT IN AN ATMOSPHERE WHICH IS SUBSTANTIALLY NON-REDUCING WITH RESPECT TO THE SAID GARNET, IN THAT HEATING IS CARRIED OUT OVER THE TEMPERATURE RANGE OF FROM 500 DEGREES C TO 950 DEGREES C, AND IN THAT HEATING IS CONTINUED FOR A PERIOD OF AT LEAST 5 MINUTES, UP TO A MAXIMUM OF APPROXIMATELY 2 HOURS.
Claim 2
Dependent Claim
143 words
METHOD FOR ALTERING A MAGNETIC PROPERTY OF A BODY OF AN IRON-CONTAINING COMPOSITION OF THE GARNET STRUCTURE, SUCH COMPOSITION CONTAINING AT LEAST 5 CATION PERCENT OF A SUBSTITUTIONAL ION OTHER THAN IRON IN THE TETRAHEDRAL AND OCTAHEDRAL CRYSTALLOGRAPHIC SITES BASED ON THE TOTAL NUMBER OF CATIONS IN SUCH SITES, SAID METHOD COMPRISING HEATING OF SAID BODY, CHARACTERIZED IN THAT AT LEAST A PORTION OF THE SAID BODY IS IN INTIMATE CONTACT WITH ELEMENTAL SILICON DURING AT LEAST A PORTION OF THE SAID HEATING, IN THAT HEATING IS CARRIED OUT IN AN ATMOSPHERE WHICH IS SUBSTANTIALLY NON-REDUCING WITH RESPECT TO THE SAID GARNET, IN THAT HEATING IS CARRIED OUT OVER THE TEMPERATURE RANGE OF FROM 500 DEGREES C TO 950 DEGREES C, AND IN THAT HEATING IS CONTINUED FOR A PERIOD OF AT LEAST 5 MINUTES, UP TO A MAXIMUM OF APPROXIMATELY 2 HOURS.
Claim 3
Dependent Claim
16 words
Method of claim 1 in which the said body is an epitaxial layer on a substrate.
Claim 4
Dependent Claim
15 words
Method of claim 1 in which said body is that of a bulk grown crystal.
Claim 5
Dependent Claim
13 words
Method of claim 1 in which the silicon is removed subsequent to heating.
Claim 6
Dependent Claim
12 words
Method of claim 1 in which the said substitutional ion is non-magnetic.
Claim 7
Dependent Claim
20 words
Method of claim 5 in which the said nonmagnetic ion is selected from the group consisting of gallium and aluminum.
Claim 8
Dependent Claim
22 words
Method of claim 1 in which only a portion of the said body is in intimate contact with the said elemental silicon.
Claim 9
Dependent Claim
16 words
Method of claim 7 in which the said elemental silicon is contained in a deposited layer.
Claim 10
Dependent Claim
14 words
Method of claim 8 in which the said deposited layer is produced by sputtering.
Claim 11
Dependent Claim
14 words
Method of claim 8 in which the said deposited layer is produced by evaporation.
Claim 12
Dependent Claim
45 words
Method of claim 10 in which net magnetization in the said body is primarily due to a predominance of iron ions in the tetrahedral sites and in which magnetization is reduced during heating preferentially in the garnet regions in intimate contact with the elemental silicon.
Claim 13
Dependent Claim
45 words
Method of claim 10 in which net magnetization in the said body is primarily due to a predominance of iron ions in the octahedral sites and in which magnetization is increased during heating preferentially in the garnet regions in intimate contact with the elemental silicon.
Claim 14
Dependent Claim
14 words
Method of claim 8 in which the said portion corresponds with the deposited pattern.
Claim 15
Dependent Claim
15 words
Method of claim 13 in which the pattern is produced photolithographically in the Si film.
References Cited (Backward Citations)
US3759745A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |