US4337162A
Expired / Lapsed
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Internal boundary layer ceramic compositions
Assignee: University of Illinois Foundation
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Filing: 1980-05-20
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Granted: 1982-06-29
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Expires: 2000-05-20
Abstract
Abstract An improved polycrystalline semiconducting ceramic composition comprises an alkaline earth metal titanate doped with a hexavalent metal oxide such as (MO 3 )(Bi 2 O 3 ) x where M is tungsten or molybdenum, and x ranges from 0 to 7, which is liquid phase sintered with lead germanate to produce internal insulating boundaries. The composition is fine grained and provides thin-layer, multi-layer capacitors that exhibit high dielectric constant values, low dissipation factors, and low temperature and voltage coefficients of capacitance.
Inventors
- 👤 David A. Payne
- 👤 Sang M. Park
- 👤 Otto C. Jahnke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:14
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/4684; H; H01; H01B; H01B3/00; H01B3/02; H01B3/12; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1272; H01G4/1281
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
115 words
A semi-conducting composition having a grain size less than 10 microns comprising: about 55.0-99.98% by weight of a polycrystalline alkaline earth metal titanate; about 0.01-10% by weight of a hexavalent metal oxide having the formula (MO 3 )(Bi 2 O 3 ) x , where M is tungsten or molybdenum and x is 0-7, said oxide being incorporated in said titanate to provide semiconductivity thereto; and about 0.01-35% by weight of a lead germanate composition having the formula (PbO) x (GeO 2 ) y-z (SiO 2 ) z where x is 1-6, y is 1-3, and z is 0-0.75y, said lead germanate composition forming an insulating boundary layer about the grains of said semiconducting titanate.
Claim 2
Dependent Claim
115 words
A semi-conducting composition having a grain size less than 10 microns comprising: about 55.0-99.98% by weight of a polycrystalline alkaline earth metal titanate; about 0.01-10% by weight of a hexavalent metal oxide having the formula (MO 3 )(Bi 2 O 3 ) x , where M is tungsten or molybdenum and x is 0-7, said oxide being incorporated in said titanate to provide semiconductivity thereto; and about 0.01-35% by weight of a lead germanate composition having the formula (PbO) x (GeO 2 ) y-z (SiO 2 ) z where x is 1-6, y is 1-3, and z is 0-0.75y, said lead germanate composition forming an insulating boundary layer about the grains of said semiconducting titanate.
Claim 3
Dependent Claim
14 words
The composition of claim 1 wherein said alkaline earth metal titanate is strontium titanate.
Claim 4
Dependent Claim
18 words
The composition of claim 2 wherein said lead germanate composition is Pb 5 Ge 3 O 11 .
Claim 5
Dependent Claim
13 words
The composition of claim 3 wherein said metal oxide is WO 3 .
Claim 6
Dependent Claim
15 words
The composition of claim 3 wherein said metal oxide is Bi 2 WO 6 .
Claim 7
Dependent Claim
161 words
A semi-conducting ceramic composition having a grain size less than 10 microns produced by the steps of: (a) calcining at a temperature of about 1000°-1400° C. about 90-99.99% by weight of a fine particle size polycrystalline alkaline earth metal titanate with about 0.01 to 10% by weight of a hexavalent metal oxide having the formula (MO 3 )(Bi 2 O 3 ) x , where M is tungsten or molybdenum and x is 0.0-7, whereby said titanate is rendered semiconducting; (b) mixing the product of step (a) with about 0.01-35% by weight of a lead germanate composition having the formula (PbO) x (GeO 2 ) y-z (SiO 2 ) z , where x is 1-6, y is 1-3, and z is 0.0-0.75y; and (c) firing the mixture of step (b) at a temperature of about 850°-1300° C. to provide by liquid-phase sintering an insulating boundary layer of said lead germanate composition about the grains of said semiconducting alkaline earth metal titanate.
Claim 8
Dependent Claim
161 words
A semi-conducting ceramic composition having a grain size less than 10 microns produced by the steps of: (a) calcining at a temperature of about 1000°-1400° C. about 90-99.99% by weight of a fine particle size polycrystalline alkaline earth metal titanate with about 0.01 to 10% by weight of a hexavalent metal oxide having the formula (MO 3 )(Bi 2 O 3 ) x , where M is tungsten or molybdenum and x is 0.0-7, whereby said titanate is rendered semiconducting; (b) mixing the product of step (a) with about 0.01-35% by weight of a lead germanate composition having the formula (PbO) x (GeO 2 ) y-z (SiO 2 ) z , where x is 1-6, y is 1-3, and z is 0.0-0.75y; and (c) firing the mixture of step (b) at a temperature of about 850°-1300° C. to provide by liquid-phase sintering an insulating boundary layer of said lead germanate composition about the grains of said semiconducting alkaline earth metal titanate.
Claim 9
Dependent Claim
14 words
The composition of claim 6 wherein said alkaline earth metal titanate is strontium titanate.
Claim 10
Dependent Claim
18 words
The composition of claim 7 wherein said lead germanate composition is Pb 5 Ge 3 O 11 .
Claim 11
Dependent Claim
13 words
The composition of claim 8 wherein said metal oxide is WO 3 .
Claim 12
Dependent Claim
15 words
The composition of claim 8 wherein said metal oxide is Bi 2 WO 6 .
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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |