US5032559A
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Method of preparing barium, titanium, zirconium oxide ferroelectric ceramic compositions
Assignee: Osram Sylvania Inc
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Filing: 1990-05-21
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Granted: 1991-07-16
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Expires: 2010-05-21
Abstract
Abstract A procedure used to prepare Ba(Ti 1-x ),Zr x )O 3 compositions wherein 0<x<0.25 having a more completely randomized distribution of Ti and Zr atoms on the TiO 2 sublattice of barium titanate is described. In accordance with the present invention there is provided a method for preparing barium titanium zirconium oxide ferroelectic ceramic. The present method comprises mixing tetraalkyl titanate and alkyl zirconate in appropriate amounts to produce (Ti 1-x Zr x )alkoxide wherein 0<x<0.25; reacting (Ti 1-x Zr x ) alkoxide wherein 0<x<0.25 to form (Ti 1-x Zr x )O 2 wherein 0<x<0.25 admixing (Ti 1-x Zr x )O 2 with BaCO 3 , said BaCO 3 being added in a molar ratio greater than 1 relative to (Ti 1-x Zr x )O 2 ; heating the admixture for a period of time and at a temperature sufficient to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x<0.25. The improved randomization of the Ti and Zr atom distributions results in a ferroelectric ceramic material having squarer electrical polarization hysteresis loops and higher remanent polarization values than can be obtained from conventionally prepared materials of similar composition.
Inventors
- 👤 Robert T. McSweeney
- 👤 Karlene Zuk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:00
CPC Classifications
C; C01; C01G; C01G25/00; C01G25/006; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2002/76; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/80; C01P2006/00; C01P2006/12; C01P2006/42; C01P2006/60
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
140 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method comprising: (a) reacting tetraalkyl titanate and tetraalkyl zirconate in appropriate amounts to produce (Ti 1-x Zr x )-alkoxide wherein 021 x≦0.25; (b) reacting said (Ti 1-x Zr x )-alkoxide to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with a BaO precursor, said BaO precursor, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU1## having a value greater than 1; and (d) heating the admixture for a period of time and at a sufficient temperature to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
Claim 2
Independent Claim
140 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method comprising: (a) reacting tetraalkyl titanate and tetraalkyl zirconate in appropriate amounts to produce (Ti 1-x Zr x )-alkoxide wherein 021 x≦0.25; (b) reacting said (Ti 1-x Zr x )-alkoxide to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with a BaO precursor, said BaO precursor, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU1## having a value greater than 1; and (d) heating the admixture for a period of time and at a sufficient temperature to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
Claim 3
Dependent Claim
83 words
A method in accordance with claim 1 wherein said step of reacting said (Ti 1-x Zr x )-alkoxide to form TiZrO 4 and (Ti 1-s Zr s )O 2 comprises: hydrolyzing said (Ti 1-x Zr x )-alkoxide to form a precipitate; isolating said precipitate; and heating said precipitate for a sufficient period of time and at a sufficient temperature to form TiZrO 4 and (Ti 1-s Zr s )O 2 wherein s is the solubility limit for ZrO 2 in TiO 2 .
Claim 4
Dependent Claim
32 words
A method in accordance with claim 2 wherein said tetraalkyl titanate includes alkyl groups which are straight, branched, or cyclic alkyl groups having from 1 to 12 carbon atoms per alkyl group.
Claim 5
Dependent Claim
21 words
A method in accordance with claim 3 wherein said alkyl groups have from 2 to 8 carbon atoms per alkyl group.
Claim 6
Dependent Claim
21 words
A method in accordance with claim 9 wherein said alkyl groups have from 4 to 6 carbon atoms per alkyl group.
Claim 7
Dependent Claim
32 words
A method in accordance with claim 2 wherein said tetraalkyl zirconate includes alkyl groups which are straight, branched, or cyclic alkyl groups having from 1 to 12 carbon atoms per alkyl group.
Claim 8
Dependent Claim
21 words
A method in accordance with claim 6 wherein said alkyl groups have from 2 to 8 carbon atoms per alkyl group.
Claim 9
Dependent Claim
21 words
A method in accordance with claim 7 wherein said alkyl groups have from 4 to 6 carbon atoms per alkyl group.
Claim 10
Dependent Claim
24 words
A method in accordance with claim 2 wherein said precipitate is heated at a temperature of from about 500° C. to about 1300620 C.
Claim 11
Dependent Claim
24 words
A method in accordance with claim 2 wherein said precipitate is heated at a temperature of from about 700° C. to about 1100620 C.
Claim 12
Dependent Claim
56 words
A method in accordance with claim 2 wherein said step of heating the admixture of said (Ti 1-s Zr s )O 2 , TiZrO 4 , and BaO precursor to produce Ba(Ti 1-s Zr s )O 3 wherein 0<x≦0.25 is carried out at a temperature in the range of from about 1000° to about 1400° C.
Claim 13
Dependent Claim
18 words
A method in accordance with claim 11 wherein the temperature if from about 1200° to about 1280° C.
Claim 14
Dependent Claim
27 words
A method in accordance with claim 1 wherein said BaO precursor is selected from the group consisting of barium carbonate, barium nitrate, barium chloride, and barium acetate.
Claim 15
Dependent Claim
14 words
A method in accordance with claim 13 wherein said BaO precursor is barium carbonate.
Claim 16
Dependent Claim
14 words
A method in accordance with claim 13 wherein said BaO precursor is barium nitrate.
Claim 17
Dependent Claim
14 words
A method in accordance with claim 13 wherein said BaO precursor is barium chloride.
Claim 18
Dependent Claim
14 words
A method in accordance with claim 13 wherein said BaO precursor is barium acetate.
Claim 19
Independent Claim
129 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method comprising: (a) preparing (Ti 1-x Zr x )-alkoxide wherein 0<x≦0.25; (b) reacting said (Ti 1-x Zr x )-alkoxide to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with a BaO precursor, said BaO precursor, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU2## having a value greater than 1; and (d) heating the admixture for a period of time and at a sufficient temperature to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
Claim 20
Independent Claim
129 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method comprising: (a) preparing (Ti 1-x Zr x )-alkoxide wherein 0<x≦0.25; (b) reacting said (Ti 1-x Zr x )-alkoxide to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with a BaO precursor, said BaO precursor, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU2## having a value greater than 1; and (d) heating the admixture for a period of time and at a sufficient temperature to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
Claim 21
Independent Claim
186 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method consisting of the steps: (a) reacting tetrabutyl titanate and n-butyl zirconate in appropriate amounts to produce (Ti 1-x Zr x )-alkoxide wherein 0<x≦0.25; (b) hydrolyzing said (Ti 1-x Zr x )-alkoxide to form a slurry; (c) drying said slurry to obtain a precipitate; (d) calcining said precipitate at a temperature in the range of from about 700° C. to about 1100° C. for a sufficient period of time to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with barium carbonate, said barium carbonate, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU3## having a value greater than 1; and (d) heating the admixture for a period of time and at a temperature of from about 1200° C. to about 1280° C. to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
Claim 22
Independent Claim
186 words
A method for preparing a barium titanium zirconium oxide ferroelectric ceramic composition, said method consisting of the steps: (a) reacting tetrabutyl titanate and n-butyl zirconate in appropriate amounts to produce (Ti 1-x Zr x )-alkoxide wherein 0<x≦0.25; (b) hydrolyzing said (Ti 1-x Zr x )-alkoxide to form a slurry; (c) drying said slurry to obtain a precipitate; (d) calcining said precipitate at a temperature in the range of from about 700° C. to about 1100° C. for a sufficient period of time to form a two phase mixture of TiZrO 4 and (Ti 1-s Zr s )O 2 , wherein s is the solubility limit for ZrO 2 in TiO 2 ; (c) admixing said (Ti 1-s Zr s )O 2 and TiZrO 4 with barium carbonate, said barium carbonate, (Ti 1-s Zr s )O 2 and TiZrO 4 being present in a molar ratio of ##EQU3## having a value greater than 1; and (d) heating the admixture for a period of time and at a temperature of from about 1200° C. to about 1280° C. to produce Ba(Ti 1-x Zr x )O 3 wherein 0<x≦0.25.
References Cited (Backward Citations)
US3330697A
Cited
US3759683A
Cited
US3847583A
Cited
US3699044A
Cited
US4086649A
Cited
US4404029A
Cited
US4360762A
Cited
US4517496A
Cited
US4616289A
Cited
JPS58198491A
Cited
JPS58199719A
Cited
JPS59195576A
Cited
JPS59195575A
Cited
US4543341A
Cited
US4537865A
Cited
US4606906A
Cited
JPS60246222A
Cited
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