EP0042009A1
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EP
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Internal boundary layer ceramic compositions and process for their production
Assignee: University of Illinois at Urbana-Champaign
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Filing: 1980-06-11
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Granted: —
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Expires: 2000-06-11
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 or capacitance.
Inventors
- 👤 David A. Payne
- 👤 Sang Moo Park
- 👤 Otto C. Jahnke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 13:37
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/47; H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1272; H01G4/1281
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
96 words
A semiconducting ceramic composition comprising a major amount of a polycrystalline alkaline earth metal titanate, doped with a small amount of a metal oxide capable of providing an n-type semiconductivity, and a minor amount of a lead germanate composition having the formula where x ranges from 1 to 6, y-ranges from 1 to 3, and z ranges from 0.0 to 0.75y, the ceramic composition being characterized in that the lead germanate composition is incorporated therein by liquid phase sintering and provides an insulated boundary layer about the grains of the polycrystalline semiconducting alkaline earth metal titanate.
Claim 2
Dependent Claim
96 words
A semiconducting ceramic composition comprising a major amount of a polycrystalline alkaline earth metal titanate, doped with a small amount of a metal oxide capable of providing an n-type semiconductivity, and a minor amount of a lead germanate composition having the formula where x ranges from 1 to 6, y-ranges from 1 to 3, and z ranges from 0.0 to 0.75y, the ceramic composition being characterized in that the lead germanate composition is incorporated therein by liquid phase sintering and provides an insulated boundary layer about the grains of the polycrystalline semiconducting alkaline earth metal titanate.
Claim 3
Dependent Claim
25 words
The compositions of Claim 1 wherein the alkaline earth metal titanate is strontium titanate derived from a mixture of SrC0 3 and Ti 0 2
Claim 4
Dependent Claim
39 words
The composition of Claim 1 wherein the alkaline earth metal titanate is strontium titanate and the metal oxide is a hexavalent metal oxide having the formula where M is tungsten or molybdenum, and x ranges from 0.0 to 7.
Claim 5
Dependent Claim
27 words
The composition of Claim 1 wherein the alkaline earth metal titanate is strontium titanate and the metal oxide is WO 3 or Bi 2 WO 6 .
Claim 6
Dependent Claim
38 words
The composition of Claim 3 comprising from about 55 to about 99.98% of strontium titanate, from about 0.01 to about 10% of the hexavalent metal oxide, and from about 0.01 to about 35% of the lead germanate composition.
Claim 7
Dependent Claim
45 words
The composition of Claim 4 comprising from about 55 to about 99.98% of strontium titanate, from about 0.01 to about 10% of W0 3 or Bi 2 Wo 6 , and from about 0.01 to about 35% of Pb 5 Ge 3 O 11 .
Claim 8
Independent Claim
112 words
A method of producing a semiconducting ceramic composition having internal insulating boundary layers which method comprises the steps of: (a) calcining in air or a weakly reducing atmosphere a polycrystalline alkaline earth metal titanate with a small amount of a metal oxide capable of providing n-type semiconductivity; (b) milling and blending the product of step (a) with a lead germanate composition having the formula where x ranges from 1 to 6, y ranges from 1 to 3, and z ranges from 0.0 to 0.75y; and (c) firing the mixture of step (b) to provide by liquid phase sintering the insulating boundary layers about the grains of the polycrystalline alkaline earth metal titanate.
Claim 9
Independent Claim
112 words
A method of producing a semiconducting ceramic composition having internal insulating boundary layers which method comprises the steps of: (a) calcining in air or a weakly reducing atmosphere a polycrystalline alkaline earth metal titanate with a small amount of a metal oxide capable of providing n-type semiconductivity; (b) milling and blending the product of step (a) with a lead germanate composition having the formula where x ranges from 1 to 6, y ranges from 1 to 3, and z ranges from 0.0 to 0.75y; and (c) firing the mixture of step (b) to provide by liquid phase sintering the insulating boundary layers about the grains of the polycrystalline alkaline earth metal titanate.
Claim 10
Dependent Claim
25 words
The method of Claim 7 wherein the alkaline eart metal titanate is strontium titanate derived from a mixture of SrC0 3 and TiO 2 .
Claim 11
Dependent Claim
39 words
The method of Claim 7 wherein the alkaline earth metal titanate is strontium titanate and the metal oxide is a hexavalent metal oxide having the formula where M is tungsten or molybdenum, and x ranges from 0.0 to 7.
Claim 12
Dependent Claim
27 words
The method of Claim 7 wherein the alkaline earth metal titanate is strontium titanate and the metal oxide is W0 3 or Bi 2 WO 6 .
Claim 13
Dependent Claim
87 words
ll. The method of Claim 9 which includes: (a) calcining at a temperature of from about 1000 to about 1400° C from about 55 to about 99.98% of fine particle size strontium titanate with from about 0.01 to about 10% of the metal oxide; (b) milling and blending the product of step (a) with from about 0.01 to about 35% of the lead germanate composition; and (c) firing the mixture of step (b) at a temperature in the range of from about 850 to about 1300° C.
Claim 14
Dependent Claim
93 words
The method of Claim 10 which includes: (a) calcining at a temperature of from about 100 to about 1400°C from about 55 to about 99.98% of fine particle size strontium titanate with from about 0.01 to about 10% of W0 3 or Bi 2 Wo 6 ; (b) milling and blending the product of step (b) with from about 0.01 to about 35% of Pb 5 Ge 3 O 11 ; and (c) firing the mixture of step (b) at a temperature in the range of from about 850 to about 1300° C.
References Cited (Backward Citations)
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