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US4033906A
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Ceramics having nonlinear voltage characteristics and method for producing same
Assignee: Fuji Electric Co Ltd
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Filing: 1975-06-03
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Granted: 1977-07-05
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Expires: 1995-06-03
Abstract
Abstract Ceramics having nonlinear voltage characteristics comprising the product obtained on preparing a mixture of zinc oxide as a main component, and, as subcomponents, cobalt plus one of praseodymium or terbium, either in an elemental form or as a compound thereof, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium, and calcining the mixture at a temperature in the range of from about 1150° to about 1400° C and a method for preparing the ceramics. An embodiment includes, as an additional subcomponent, lanthanum, either in an elemental form or as a compound in an amount of from 0.08 to 8.0 atomic %, calculated as lanthanum, with the zinc oxide, cobalt and praseodymium.
Inventors
- 👤 Ikuo Nagasawa
- 👤 Kazuo Mukae
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:36
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
86 words
A ceramic having non-linear voltage characteristics consisting essentially of the calcined product obtained on calcining in air a mixture of (a) zinc oxide as a principal component and (b) cobalt plus one of praseodymium or terbium, either in elemental form or as a compound thereof, as subcomponents, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium.
Claim 2
Dependent Claim
86 words
A ceramic having non-linear voltage characteristics consisting essentially of the calcined product obtained on calcining in air a mixture of (a) zinc oxide as a principal component and (b) cobalt plus one of praseodymium or terbium, either in elemental form or as a compound thereof, as subcomponents, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium.
Claim 3
Dependent Claim
20 words
The ceramic of claim 1, wherein said ceramic comprises zinc oxide, an oxide of cobalt and an oxide of praseodymium.
Claim 4
Dependent Claim
20 words
The ceramic of claim 1, wherein said ceramic comprises zinc oxide, an oxide of cobalt and an oxide of terbium.
Claim 5
Dependent Claim
41 words
The ceramic of claim 1, wherein said mixture further contains zinc oxide, cobalt, and praseodymium and additionally lanthanum, either in an elemental form or as a compound thereof, in an amount of from 0.08 to 8.0 atomic %, calculated as lanthanum.
Claim 6
Independent Claim
104 words
A method for producing a ceramic having non-linear voltage characteristics comprising preparing a mixture of (a) zinc oxide, as a main component and the remainder (b) cobalt plus one of praseodymium or terbium, either in elemental form or as a compound thereof as subcomponents, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium and calcining the mixture in air at a temperature in the range of from about 1150° C. to about 1400° C.
Claim 7
Independent Claim
104 words
A method for producing a ceramic having non-linear voltage characteristics comprising preparing a mixture of (a) zinc oxide, as a main component and the remainder (b) cobalt plus one of praseodymium or terbium, either in elemental form or as a compound thereof as subcomponents, in an amount of from 0.1 to 8.0 atomic % for the cobalt, from 0.08 to 8.0 atomic % for the praseodymium and from 0.1 to 8.0 atomic % for the terbium, each calculated as cobalt, praseodymium and terbium and calcining the mixture in air at a temperature in the range of from about 1150° C. to about 1400° C.
Claim 8
Dependent Claim
19 words
The method of preparing the ceramic of claim 5, wherein said calcining is at 1300° C. to 1350° C.
Claim 9
Dependent Claim
27 words
The method of preparing the ceramic of claim 5, wherein said mixture is zinc oxide and cobalt and praseodymium in electrical form or as a compound thereof.
Claim 10
Dependent Claim
26 words
The method of preparing the ceramic of claim 5, wherein said mixture is zinc oxide and cobalt and terbium in elemental form or a compound thereof.
Claim 11
Dependent Claim
38 words
The method of producing the ceramic of claim 5, wherein said mixture further contains lanthanum, either in an elemental form or as a compound thereof in an amount of from 0.08 to 8.1 atomic %, calculated as lanthanum.
Claim 12
Dependent Claim
19 words
The ceramic of claim 1 obtained when in addition to calcining said mixture, said mixture is precalcined in air.
Claim 13
Dependent Claim
15 words
The method of claim 5 including the additional step of precalcining said mixture in air.
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) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |