US4882652A
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High dielectric constant type ceramic composition
Assignee: Toshiba Corp
•
Filing: 1987-11-02
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Granted: 1989-11-21
•
Expires: 2007-11-02
Abstract
Abstract When a portion of the Pb of a Pb(Zn 1/3 Nb 2/3 )O 3 -based ceramic composition within the region bounded by lines connecting a, b, c, d, e and f points in the ternary composition diagram of the accompanying FIG. 1 is substituted by a small amount of Ca, a high dielectric constant type ceramic composition is obtained which has a small temperature coefficient of dielectric constant and which is effective as a material for multilayer ceramic capacitors.
Inventors
- 👤 Osamu Furukawa
- 👤 Mitsuo Harata
- 👤 Takaaki Yasumoto
- 👤 Motomasa Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:01
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/495; C04B35/497; C04B35/499
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A high dielectric constant ceramic composition, characterized in that said composition is represented by the general formula: xPb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -- yPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 --zPbTiO.sub.3, wherein a portion of Pb of the composition within lines connecting the following points a, b, c, d, e' and f' of a ternary composition diagram having the following apexes of respective components, is substituted by from 2 to 30 mole % of calcium: ______________________________________
a: (x = 0.60,
y = 0.40,
z = 0.00)
b: (x = 0.60,
y = 0.05,
z = 0.35)
c: (x = 0.45,
y = 0.05,
z = 0.50)
d: (x = 0.01,
y = 0.49,
z = 0.50)
e' (x = 0.01,
y = 0.8, z = 0.19)
f' (x = 0.5, y = 0.5, z = 0)
______________________________________
Claim 2
Dependent Claim
129 words
A high dielectric constant ceramic composition, characterized in that said composition is represented by the general formula: xPb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -- yPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 --zPbTiO.sub.3, wherein a portion of Pb of the composition within lines connecting the following points a, b, c, d, e' and f' of a ternary composition diagram having the following apexes of respective components, is substituted by from 2 to 30 mole % of calcium: ______________________________________
a: (x = 0.60,
y = 0.40,
z = 0.00)
b: (x = 0.60,
y = 0.05,
z = 0.35)
c: (x = 0.45,
y = 0.05,
z = 0.50)
d: (x = 0.01,
y = 0.49,
z = 0.50)
e' (x = 0.01,
y = 0.8, z = 0.19)
f' (x = 0.5, y = 0.5, z = 0)
______________________________________
Claim 3
Dependent Claim
62 words
The high dielectric constant ceramic composition according to claim 1, wherein when lead and calcium elements are represented by A, further zinc, magnesium, niobium and titanium elements are represented by B and the chemical formula of the complex compound is represented by ABO 3 , the molar ratio of A to B is in the range shown in the formula: 1.00≦A/B <1.10
Claim 4
Dependent Claim
49 words
The high dielectric constant ceramic composition according to claim 1 which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 5
Dependent Claim
26 words
The high dielectric constant ceramic composition according to claim 1, wherein b is b' (x=0.6, y=0.2, and z=0.2), and c is c' ((x=0.3, y=0.2, and z=0.5).
Claim 6
Dependent Claim
16 words
The high dielectric constant ceramic composition according to claim 1, wherein z is at least 0.01.
Claim 7
Dependent Claim
30 words
A multilayer ceramic capacitor having at least a pair of internal electrodes, said capacitor being produced using the high dielectric constant ceramic composition according to claim 1 as a dielectric.
Claim 8
Dependent Claim
27 words
The capacitor according to claim 6, wherein the electrodes are formed from a low melting metal selected from the group consisting of silver, copper, nickel and aluminum.
Claim 9
Dependent Claim
49 words
The high dielectric constant ceramic composition according to claim 2, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 10
Dependent Claim
49 words
The high dielectric constant ceramic composition according to claim 3, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 11
Dependent Claim
49 words
The high dielectric constant ceramic composition according to claim 4, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
Claim 12
Dependent Claim
49 words
The high dielectric constant ceramic composition according to claim 5, which further comprises at least one of manganese, cobalt, nickel and chromium which is additionally included therein in an amount of up to 1.0 mole % on the basis of MnO, CoO, NiO and Cr 2 O 3 .
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