US4295989A
Expired / Lapsed
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Luminescent hafnia composition
Assignee: United States Department of the Navy
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Filing: 1980-06-23
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Granted: 1981-10-20
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Expires: 2000-06-23
Abstract
Abstract A cubia, yttria stabilized halnia phosphor, doped with Ce 3+ , has beeniscovered. The phosphor has a blue luminescence, peaking at about 4200 A, with a secondary peak in the 3800-4000 A region. The optimum composition is 3hfO 2 :Y 2 O 3 :Ce 3+ where the Ce 3+ dopant ranges from 0.1-1.0 weight %.
Inventors
- 👤 Philipp H. Klein
- 👤 Arrigo Addamiano
- 👤 Roger Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:10
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
29 words
A blue-luminescing material of 3HfO 2 :Y 2 O 3 with a Ce 3+ dopant in an amount of 0.1 to 1.0 weight percent exhibiting a cubic crystalline structure.
Claim 2
Dependent Claim
29 words
A blue-luminescing material of 3HfO 2 :Y 2 O 3 with a Ce 3+ dopant in an amount of 0.1 to 1.0 weight percent exhibiting a cubic crystalline structure.
Claim 3
Dependent Claim
20 words
A luminescent material as claimed in claim 1 where the concentration of Ce 3+ dopant is about 0.4 weight %.
Claim 4
Dependent Claim
144 words
A process for producing a cubic luminescent material of the formula 3HfO 2 :Y 2 O 3 :Ce 3+ wherein Ce 3+ dopant is present in an amount from 0.1 to 1.0 weight percent which comprises forming a mixture of pure HfO 2 with substantially pure Y 2 O 3 in a HfO 2 :Y 2 O 3 ratio of 3:1; adding an aqueous solution of a cerium salt thereto; evaporating the resultant paste to a dry powder; placing the resultant powder in a container made from a member of the group consisting of Vitreosil, Alundum, graphite, and pyrolytic boron nitride; heating the powder about 1300° C. under a neutral or slightly reducing atmosphere for a period of about 2 to about 100 hours; cooling to room temperature, and heating in an oxidizing atmosphere at about 1000° C. for about 1 to 10 hours.
Claim 5
Dependent Claim
144 words
A process for producing a cubic luminescent material of the formula 3HfO 2 :Y 2 O 3 :Ce 3+ wherein Ce 3+ dopant is present in an amount from 0.1 to 1.0 weight percent which comprises forming a mixture of pure HfO 2 with substantially pure Y 2 O 3 in a HfO 2 :Y 2 O 3 ratio of 3:1; adding an aqueous solution of a cerium salt thereto; evaporating the resultant paste to a dry powder; placing the resultant powder in a container made from a member of the group consisting of Vitreosil, Alundum, graphite, and pyrolytic boron nitride; heating the powder about 1300° C. under a neutral or slightly reducing atmosphere for a period of about 2 to about 100 hours; cooling to room temperature, and heating in an oxidizing atmosphere at about 1000° C. for about 1 to 10 hours.
Claim 6
Dependent Claim
34 words
A method as claimed in claim 3 where a mineralizer in an amount up to one weight percent is added with the cercium salt to the mix to effect a more uniform luminescent material.
Claim 7
Dependent Claim
22 words
The method of claim 4 wherein said oxidizing atmosphere is air and said heating in air is from 1 to 3 hours.
Claim 8
Dependent Claim
26 words
The method of claim 5 wherein said cerium salt is selected from the class consisting of cerium nitrate and the double nitrate of cerium and magnesium.
Claim 9
Dependent Claim
28 words
The method of claim 6 wherein said mineralizer is selected from the class consisting of NaNO 3 , LiNO 3 , Mg(NO 3 ) 2 , and LiCl.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein said mineralizer is selected from the class consisting of NaNO 3 and LiCl.
Claim 11
Dependent Claim
9 words
The product produced by the method of claim 4.
Claim 12
Dependent Claim
38 words
A method as claimed in claim 3 where the mixture is fired to about 1300° C. while in a pyrolytic boron nitride boat, under an atmosphere of Ar, or a 99% N 2 , 1% H 2 atmosphere.
Claim 13
Dependent Claim
9 words
The product produced by the method of claim 3.
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) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |