Barium Titanate Patents (Class 501/137)
  • Patent number: 5656073
    Abstract: The intermediate product which is used in a method of making a molded arte, especially an endless PZT fiber, is itself made by a method including mixing an organic zirconium compound, Zr(OR.sup.1).sub.4, and an organic titanium compound, Ti(OR.sup.2).sub.4, R.sup.1 and R.sup.2 being C.sub.1 - to C.sub.10 -alkyl groups, separately or together with 0 to 4 moles of at least one alcohol of the formula R.sup.3 --X--R.sup.4 --OH or R.sup.3 --CX--R.sup.4 --OH, X being O, S or an amine group and R.sup.3 and R.sup.4 being C.sub.1 - to C.sub.10 -alkyl groups, per mole of the zirconium and titanium compounds; reacting the zirconium and titanium compounds in the resulting mixture or mixtures with one to three moles of at least one C.sub.2 - to C.sub.10 -carboxylic acid per mole of the zirconium and titanium compounds to form at least one reaction mixture; mixing the at least one reaction mixture and reacting with 1 to 1.
    Type: Grant
    Filed: July 18, 1996
    Date of Patent: August 12, 1997
    Assignee: Fraunhofer-Gesellschaft zur Forderung der Angewandten Forschung e.V.
    Inventors: Walther Glaubitt, Rainer Jahn, Stephan Merklein
  • Patent number: 5656562
    Abstract: A method for improving the properties of ceramic green bodies is provided. In particular, ceramic green bodies having improved green strength are provided. Incorporating certain acid-containing polymers as binders at a level of at least about 1 to about 15, preferably at least about 3 to about 10 percent by weight based on the weight of ceramic particles improves the green strength of the resulting ceramic green bodies.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: August 12, 1997
    Inventor: Xianliang Wu
  • Patent number: 5650367
    Abstract: A dielectric ceramic composition containing, per 100 parts by weight of BaTiO.sub.3, at least either one of Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 in an amount of from 0.8 to 3.5 parts by weight, MgO in an amount of from 0.06 to 0.7 parts by weight, oxides of rare earth elements in an amount of from 0.005 to 0.520 parts by weight, and MnO in an amount of from 0.01 to 0.30 parts by weight in the form of MnCO.sub.3, the molar ratio of MgO to either Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 being from 0.5 to 2.2. The dielectric ceramic composition has a dielectric constant of not smaller than 2500, is fired at a temperature of not higher than 1300.degree. C., exhibits a change of capacitance depending upon the temperature satisfying X7R of the IEA Standards, a dielectric loss of not larger than 2.5%, a small voltage dependence, and an insulation resistance of not smaller than 10.sup.4 M.OMEGA., and is suited as a material for producing ceramic capacitors and resonators.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: July 22, 1997
    Assignee: Kyocera Corporation
    Inventors: Nobuyoshi Fujikawa, Yoshihiro Fujioka, Yasushi Yamakuchi, Shin-ichi Osawa, Hiroshi Ojima
  • Patent number: 5645634
    Abstract: A composition comprising Ba and Sr salts of carboxylic acids represented by the formula: C.sub.n H.sub.2n+1 COOH wherein 3.ltoreq.n.ltoreq.7, and having structures represented by the following formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 each represent a hydrogen atom, a methyl group or an ethyl group, and M represents Ba or Sr, can be used to form thin films of Ba.sub.1-x Sr.sub.x Ti.sub.y O.sub.3. A composition comprising a barium carboxylate, a strontium carboxylate and a titanium alkoxide in a mixed solvent of a carboxylic acid and an ester, can also be used to form Ba.sub.1-x Sr.sub.x Ti.sub.y O.sub.3 thin films. The proportion of the mixed solvent is 2-11 molar times as much as the Ti. A composition comprising salts of carboxylic acids represented by R.sup.a COOH wherein R.sup.a is a linear or branched alkyl group having 3-7 carbon atoms, as the Ba and Sr sources, and Ti(OR.sup.b).sub.4 wherein R.sup.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: July 8, 1997
    Assignee: Mitsubishi Materials Corporation
    Inventors: Katumi Ogi, Tadashi Yonezawa, Tsutomu Atsuki, Keiko Endo
  • Patent number: 5646080
    Abstract: A sinterable dielectric ceramic powder composition comprising 95 to 98 parts by weight of a major ingredient consisting of 97.0 to 99.5 mole % barium titanate, 0.5 to 3.0 mole % magnesium oxide or a precursor therefor and 0 to 2.0 mole % manganese oxide or a precursor therefor and 0 to 0.2 mole % cobalt oxide or a precursor therefor; 2 to 5 parts by weight of a minor ingredient consisting of a ternary mixture of 15 to 30 mole % barium oxide or a precursor therefor, 15 to 30 mole % silicon dioxide or a precursor therefor and 40 to 70 mole % calcium titanate, which composition can be fabricated into multilayer ceramic capacitors with nickel, nickel alloy, palladium or palladium/silver alloy inner electrodes, the so formed capacitors having a variation of capacitance with temperature of less than .+-.20% over the range -55.degree. C. to 140.degree. C. as compared to the value at 25.degree. C. and not containing any second phases after sintering.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: July 8, 1997
    Assignee: Tam Ceramics, Inc.
    Inventors: Mike Ssu-Hai Chu, John Bultitude, Michael Rand, Kay Louise Nimmo, Ian Thompson, Christopher Hood
  • Patent number: 5635433
    Abstract: A novel ceramic ferroelectric material having a high dielectric constant, a ow loss tangent, a low threshold voltage, a high nonlinear voltage exponent and a high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and zinc oxide (ZnO). The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 --ZnO, wherein x is greater than 0.00, but less than or equal to 0.75, and wherein the percent weight ratio between BSTO and ZnO ranges from approximately 99%-50% and 1%-50% respectively. The novel materials possess superior electronic properties, and they may be employed in multilayer capacitors, capacitor-varistors, non-volatile computer memory or phased array antenna systems.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: June 3, 1997
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Louise Sengupta
  • Patent number: 5635434
    Abstract: Ceramic ferroelectric composite material-BSTO-Magnesia based compounds hag a low dielectric constant, low loss tangent and high tunability are disclosed. The composite material comprises Barium Strontium Titanate (BSTO) and a magnesia compound selected from the group consisting, MgZrO.sub.3, MgAl.sub.2 O.sub.4, and MgTiO.sub.3. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 -magnesia compound, wherein x is greater than 0.00, but less than or equal to 0.75, and wherein the percent weight ratio between BSTO and magnesia compound ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties, and they may be employed in various antenna systems.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: June 3, 1997
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Louise Sengupta
  • Patent number: 5631624
    Abstract: A dielectric ceramics contains, at least, two kinds of metal ions and a dielectric constant changes continuously or step by step as a function of position. The metal ions contained in the dielectric ceramics are, at least, two kinds which are selected from Mg, Ca, Sr, Ba, Zn, Pb, Bi, Y, La, Ce, Nd, Sm, Gd, Er, Ti, Zr, Sn, Si and Mn, and the dielectric constant .epsilon. changes in the range of 7.ltoreq..epsilon..ltoreq.90. This dielectric ceramics is used in a dielectric substrate for stripline device, a dielectric substrate for monolithic IC and a dielectric block for polarizer. For example, when used as the dielectric substrate for stripline device, it is so formed that a dielectric constant at its center portion is constant, and that those at an outer portion becomes smaller step by step or continuously towards ends.
    Type: Grant
    Filed: August 28, 1995
    Date of Patent: May 20, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Seiji Kanba, Kazuya Kawabata, Hiroshi Takagi
  • Patent number: 5624604
    Abstract: A method for dispersing and reducing the rate of dissolution and/or hydration of colloidal ceramic suspensions is described. The method comprises adding to a ceramic suspension a non-polymeric hydroxylated organic compound. The organic compound has at least one hydroxyl group, preferably at least two hydroxyl groups. The organic compound also includes a functional group selected from the group consisting of a carboxyl, a carboxylate, a sulfonic acid, a sulfonate, a phosphoric acid, a phosphate, an amine, and a quaternary ammonium salt. The ceramic suspension typically comprises a colloidal suspension of a metal oxide, wherein the metal of the metal oxide is an alkali metal, alkaline-earth metal or a rare-earth metal, but preferably is magnesium, calcium or a rare-earth metal. The non-polymeric organic compound is added to the suspension in an amount effective to substantially disperse and reduce the rate of dissolution of the ceramic particles, such as from about 0.01 weight percent to about 5.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: April 29, 1997
    Inventors: Mehrdad Yasrebi, William W. Kemp, David H. Sturgis, Ilhan A. Aksay, Hamazo Nakagawa
  • Patent number: 5612268
    Abstract: The present invention relates to a dielectric ceramic composition, comprising from 97.5 to 99.95% by weight of{100-(a+b+c+d)}BaTiO.sub.3 +aZnO+b(2Bi.sub.2 O.sub.3.3AO.sub.2)+cTa.sub.2 O.sub.5 +dRe.sub.2 O.sub.3as main component and from 0.05 to 2.5% by weight of glass mainly comprising SiO.sub.2, and possibly also containing from 0.01 to 0.5% by weight of at least one oxides of Cr, Mn, Fe, Co, and/or Ni. A represents Zr or Sn; Re represents at least one of La, Pr, Nd, Sm, Dy and Er; and {100-(a+b+c+d)}, a, b, c, and d represent molar percent which satisfy the following relationships:______________________________________ 0.5 .ltoreq. a .ltoreq. 4.5 0.5 .ltoreq. b .ltoreq. 4.5 0.5 .ltoreq. c .ltoreq. 4.5 0.5 .ltoreq. d .ltoreq. 5.5.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: March 18, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Sakiko Iwamoto, Masamitsu Shibata, Yukio Hamaji
  • Patent number: 5609911
    Abstract: Powder of ceramic materials is produced by mixing a powder of a basic ceramic composition, a solvent and a surfactant to prepare a slurry, adding at least one unsaturated fatty acid salt containing an additive metal element to the resultant slurry, polymerizing the at least one unsaturated fatty acid salt with a polymerization initiator to form a polymer of at least one unsaturated fatty acid salt, drying the resultant slurry to form a layer of the resultant polymer on particle surfaces of the basic ceramic composition, and then calcining the resultant coated powder of the basic ceramic composition.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: March 11, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Shinsei Okabe, Shunsuke Nakaya, Yukio Hamaji, Masami Yabuuchi
  • Patent number: 5604166
    Abstract: A dielectric ceramic composition having the composition represented by formula (1):(BaTiO.sub.3).sub.e +(BaZrO.sub.3).sub.f +(CaTiO.sub.3).sub.g +(MgTiO.sub.3).sub.h +(R1+R2+R3+R4 ) (1)wherein e is from 60.3 to 67.5 mol %, f is from 11.9 to 15.6 mol %, q is from 15.8 to 23.0 mol %, and h is from 2.6 to 5.8 mol %, provided that the total of e, f, q, and h is 100 mol %; and R1 is from 0.05 to 0.4 wt % of NiO, R2 is from 0.05 to 0.3 wt % of CeO.sub.2, R3 is from 0.03 to 0.2 wt % of MnO, and R4 is from 0.0 to 0.25 wt % of SiO.sub.2, all based on 100 mol % in total of BaTiO.sub.3, BaZrO.sub.3, CaTiO.sub.3, and MgTiO.sub.3.
    Type: Grant
    Filed: February 7, 1996
    Date of Patent: February 18, 1997
    Assignee: TDK Corporation
    Inventors: Norio Sasaki, Yoshiharu Watanabe, Kouji Takahashi
  • Patent number: 5601748
    Abstract: Barium-strontium titanate ferroelectric materials and AFe.sub.2 O.sub.4 -type ferrite ferromagnetic materials may be consolidated into a ferroelectric-ferromagnetic composite having useful electromagnetic interference attenuation properties over a wide range of electromagnetic frequencies by fluxing the barium-strontium titanate with a combination of (1) a lithium compound and barium oxide or (2) copper oxide and barium oxide and thereafter mixing the fluxed ferroelectric with the ferromagnetic and sintering the combination at reduced temperature in the range of 1060.degree. C. to 1150.degree. C.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: February 11, 1997
    Assignee: General Motors Corporation
    Inventors: Said A. Mansour, Adolph L. Micheli, Joseph V. Mantese, Dennis F. Dungan
  • Patent number: 5599757
    Abstract: A low temperature fired NPO type ceramic dielectric composition is employed for making high frequency multi-layer capacitors having dielectric constants between 25 and 40 at room temperature, and which do not vary from this base line value by more than .+-.30 parts per million (PPM)/.degree.C. over a temperature range of -55.degree. C. to +125.degree. C. with the value at +25.degree. C. being the reference point. The dielectric composition is made from a base dielectric ceramic formulation and a low melting point glass formulation, each derived from metal oxides or precursors thereof. Manganese dioxide or a precursor thereof may be added in the amount of from about 0.012 to 0.060 weight percent as the dioxide based on the combined weight of the ceramic formulation and the glass formulation. The mixtures, when made into multi-layer ceramic capacitors (MLCC), are fired at or below 1120.degree. C.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: February 4, 1997
    Assignee: Ferro Corporation
    Inventors: James M. Wilson, Walter J. Symes, Jr.
  • Patent number: 5591372
    Abstract: A piezoelectric or electrostrictive composite exhibiting anisotropic 3-3 connectivity with a dense ceramic phase and an infiltrate polymer phase. The ceramic phase is an interconnected ceramic lamelli structure that is arranged substantially parallel in one direction. The ceramic lamelli have greater connectivity in the z direction than in the x and y directions, while the connectivity in the x and y directions are essentially equal.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: January 7, 1997
    Assignee: Generla Electric Company
    Inventors: Venkat S. Venkataramani, Lowell S. Smith
  • Patent number: 5592647
    Abstract: A panel heater comprising, on an upper surface of a metallic sheet (2) provided with PTC ceramics (1) on the back side thereof, a highly insulating material or an open space (4) at the portion corresponding to the back side portion to which the PTC ceramics are provided, with a material (3) for conducting heat from the metallic sheet being thus provided to the rest of the surface side of said metallic sheet, and a finishing sheet (5) being established on the upper surface of the whole structure. More preferably, the metallic sheet (2) is provided with equally spaced concave grooves with PTC ceramics (1) on the back plane of said grooves and a highly insulating material or an open space (4) inside said grooves, and a finishing sheet (5) established thereon. Accordingly, a simply structured panel heater resistant to heavy loads yet free from local overheating is provided.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: January 7, 1997
    Assignees: Nippon Tungsten Co., Ltd., Kyushu Electric Power Co., Inc.
    Inventors: Masahiro Yamauchi, Takashi Kaimoto, Mitsuhiko Furukawa, Katsutoshi Rikihisa, Hironori Yoshida, Kenji Watanabe
  • Patent number: 5578539
    Abstract: The endless PZT fiber is a lead zirconate-lead titanate mixed substance and s made by a method including the steps of mixing an organic zirconium compound, Zr(OR.sup.1).sub.4, and an organic titanium compound, Ti(OR.sup.2).sub.4, R.sup.1 and R.sup.2 each being a C.sub.1 - to C.sub.10 -alkyl group, separately or together with 0 to 4 moles of at least one alcohol of the formula R.sup.3 --X--R.sup.4 --OH or R.sup.3 --CX--R.sup.4 --OH, X being O, S or an amine group and R.sup.3 and R.sup.4 each being a C.sub.1 - to C.sub.10 -alkyl group, per mole of the zirconium and titanium compounds; reacting the zirconium compound and titanium compounds in the resulting mixture or mixtures with one to three moles of at least one C.sub.2 - to C.sub.10 -carboxylic acid per mole of the zirconium and titanium compounds to form at least one reaction mixture; mixing the at least one reaction mixture from the reacting step with 1 to 1.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: November 26, 1996
    Assignee: Fraunhofer-Gesellschaft Zur F orderung Der Angewandten Forschung e.V.
    Inventors: Walther Glaubitt, Rainer Jahn, Stephan Merklein
  • Patent number: 5557286
    Abstract: An improved BST dielectric powder is created used a sol-gel procedure. Addition of graphite to the powder, followed by a firing of the mixture results in a highly porous BST substrate, with the included graphite being burned off. By adjustment of the amount of added graphite, the porosity of the BST substrate is widely adjustable and enables achievement of a low bulk dielectric constant. A low dielectric filler is added to the fired substrate so as to provide a composite substrate with physical rigidity. Conductive layers are then adhered to the composite substrate to enable a tuning of the dielectric constant in accordance with applied DC voltage potentials. Antenna and other applications of the improved composite BST substrate are described.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: September 17, 1996
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Fathi Selmi, Vasundara V. Varadan
  • Patent number: 5552355
    Abstract: A decrease in the temperature coefficient of the dielectric constant (TCK) for polycrystalline ceramics of Barium Strontium Titanate (BST) through admixture with tetragonal bronze type Barium Strontium Niobate (BSN) has been found. For Ba.sub.0.5 Sr.sub.0.5 TiO.sub.3 ceramics, a 10% admixture of BSN decreases TCK by a factor of 2.5 at 10 MHz, with negligible degradation of the dielectric loss. A 37.5% admixture of BSN decreases TCK by a factor of more than 100. Dielectric constants for the mixtures are in the range of 200-500.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: September 3, 1996
    Assignee: AT&T Corp.
    Inventors: Robert J. Cava, James J. Krajewski, William F. Peck
  • Patent number: 5550092
    Abstract: A sinterable ceramic composition which comprises a barium titanate based dielectric precursor powder which has a temperature coefficient of capacitance, TC, of .+-.15% over the temperature range -55.degree. to 125.degree. C., in admixture with from 0.25 to 2.0% by weight of an additive which is selected from the group consisting of ZrSiO.sub.4, Al.sub.2 O.sub.3, SiO.sub.2, precursors therefor and mixtures thereof, the composition having an average particle size in the range of from 0.6 to 0.8 micrometers and, when fired, having a dielectric constant of above 2500, a TC of .+-.15% over the temperature range of -55.degree. to +125.degree. C. and a porosity of less than 0.7% with no pores greater than 3.5 micrometers average diameter.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: August 27, 1996
    Assignee: Tam Ceramics Inc.
    Inventors: Mike S.-H. Chu, John Bultitude, Christopher Hood
  • Patent number: 5543367
    Abstract: The invention is a process for decomposing dried paint sludge to recover the organic and inorganic components of the paint sludge as gaseous, liquid, and composite materials. The process comprises drying the paint sludge to remove water and organic solvents, pyrolizing the dried paint sludge in an inert atmosphere in an elevated temperature of up to about 600.degree. C. to form gaseous and liquid decomposition materials and a solid residue. The process further comprises collecting the gaseous and liquid decomposition materials and subjecting the solid residue to sintering in an elevated temperate of about 900.degree. to 1300.degree. C. in an atmosphere of nitrogen, argon or ammonia to convert the solid residue to composite materials comprising barium nitranate and titanium compounds such as titanium dioxide, titanium nitride, and titanium carbide. The gaseous and liquid materials may be further pyrolyzed to carbon materials.
    Type: Grant
    Filed: July 28, 1995
    Date of Patent: August 6, 1996
    Assignee: Ford Motor Company
    Inventors: Chaitanya K. Narula, Byung R. Kim, Irving T. Salmeen
  • Patent number: 5512196
    Abstract: A material which possesses both capacitive and inductive properties for suppressing electromagnetic interference is provided, wherein the material is a composite of a ferroelectric material and a ferromagnetic material. The ferroelectric-ferromagnetic composite material is formulated and processed so as to retain the distinct electrical properties of the individual constituents according to the relative quantities of the constituents present in the ferroelectric-ferromagnetic composite material. As a unitary composite element, the ferroelectric-ferromagnetic composite is readily formable to provide a compact electrical filter whose filtering capability is highly suitable for suppressing electromagnetic interference from sources internal and external to an automotive environment. The sintered composite has a very low porosity; interconnectivity between the ferroelectric and ferromagnetic phases; and has no chemical reaction between the ferroelectric and ferromagnetic phases to produce a third phase.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: April 30, 1996
    Assignee: General Motors Corporation
    Inventors: Joseph V. Mantese, Adolph L. Micheli, Dennis F. Dungan
  • Patent number: 5486491
    Abstract: A novel ceramic ferroelectric material having a low dielectric constant, loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 --ZrO.sub.2, wherein x is greater than 0.00, but less than or equal to 0.70, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and ZrO.sub.2 ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: January 23, 1996
    Assignee: The United States of America as represented by The Secretary of the Army
    Inventors: Louise Sengupta, Eric Ngo, Steven Stowell, Michelina O'Day, Robert Lancto
  • Patent number: 5462009
    Abstract: A method for producing a perovskite composition from a precursor composition wherein the precursor composition is irradiated with microwaves to heat the precursor composition and convert the precursor composition to perovskite. A susceptor crucible for use in processing a perovskite precursor composition. The susceptor crucible has an inner crucible, an outer crucible surrounding said inner crucible, and a susceptor material positioned between and separating the inner and outer crucibles.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: October 31, 1995
    Assignee: The Boeing Company
    Inventor: Darryl F. Garrigus
  • Patent number: 5453262
    Abstract: A continuous process for making a crystalline ceramic powder having a perovskite structure, ABO.sub.3, comprising:a. preparing a first acidic aqueous solution containing one or more elements that are insoluble precursor elements capable of forming the perovskite structure;b. preparing a second basic solution containing a sufficient concentration of hydroxide to precipitate the elements in step (a);c. mixing the first acidic solution with the second basic solution to precipitate a substantially pure mixture of hydroxides;d. washing the precipitate to remove hydroxide and salt impurities;e. forming a slurry of oxides or hydroxides of one or more of the elements that are soluble precursor elements capable of forming in the perovskite structure, and heating the slurry to a temperature sufficient to dissolve the soluble oxides or hydroxides of the soluble precursor elements;f. redispersing the washed precipitate and heating to the temperature of the soluble oxides or hydroxides of step (e);g.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: September 26, 1995
    Assignee: Battelle Memorial Institute
    Inventors: William J. Dawson, Scott L. Swartz
  • Patent number: 5453294
    Abstract: In the production of ferroelectric PZT or PLZT thin film by the sol-gel method, application of precursor solution (sol) onto a substrate is followed by heat-treatment for pyrolysis at 150.degree.-250.degree. C., 250.degree.-359.degree. C., or 450.degree.-550.degree. C., and further firing for crystallization at 500.degree.-800.degree. C., whereby crystal orientation in the direction of the (111) plane, or the (111) and (100) planes, or the (100) and (200) planes can be effected.
    Type: Grant
    Filed: April 16, 1993
    Date of Patent: September 26, 1995
    Assignee: Mitsubishi Materials Corporation
    Inventors: Katsumi Ogi, Nobuyuki Soyama, Akihiko Mieda
  • Patent number: 5451426
    Abstract: A thin film of barium titanate is formed on a substrate by immersing a substrate in an aqueous solution containing titanium ions along with a glass substance mainly comprising barium oxide and silicon dioxide. In the solution, barium ions are eluted from the glass substance with the solution to react with titanium ions in the solution to deposit barium titanate on the substrate.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: September 19, 1995
    Assignee: Murata Mfg. Co., Ltd.
    Inventors: Yoshio Abe, Hiroshi Takagi, Yukio Sakabe
  • Patent number: 5443746
    Abstract: Ferroelectric composites are prepared by sol-gel derived procedures. The present invention utilizes the sol-gel process (1) to form a gel in a mold of the desired size and shape, (2) to dry the gel using a supercritical fluid extraction, (3) to sinter the dried gel to a crystalline ceramic, and finally (4) to impregnate the pores with a low loss polymer. The aerogel composition may be a barium titanate-based composition such as barium strontium titanate (BST). Making a ferroelectric aerogel composite provides a unique and novel means of fully exploiting the voltage- and/or frequency-tunable properties of certain compositions by maximizing their desirable properties and minimizing their undesirable characteristics such as loss at operational frequencies.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: August 22, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Norman H. Harris, Brian M. Pierce, Carl W. Townsend, Thomas K. Dougherty
  • Patent number: 5427988
    Abstract: A novel ceramic ferroelectric material having a low dielectric constant, extremely low loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 --MgO, wherein x is greater than 0.00, but less than or equal to 0.75, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and MgO ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems at both microwave and millimeter wave range frequencies.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: June 27, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Louise Sengupta, Eric Ngo, Steven Stowell, Michelina O'Day, Robert Lancto
  • Patent number: 5424707
    Abstract: A NTC thermistor composition based on barium titanate has a Ba site and Ti site in a mole ratio (Ba site/Ti site) of 0.99 to 1.05, while 5 to 40 mole percent of the Ba site is substituted by Ca and not more than 40 mole percent is substituted by Sr.
    Type: Grant
    Filed: July 21, 1993
    Date of Patent: June 13, 1995
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Terunobu Ishikawa, Hideaki Niimi, Yasunobu Yoneda
  • Patent number: 5407876
    Abstract: The present invention is a dielectric ceramic composition capable forming a dielectric resonator device provided with a high Q value at a high frequency band and keep a stable crystal phase when operated at a high power applied field. The dielectric ceramic composition which comprises a base composition expressed by the following chemical formula;BaO-x{(1-y)TiO.sub.2.yZrO.sub.2 };wherein 4.300.ltoreq.x.ltoreq.4.450 0<y.ltoreq.0.10 andand additives of MnO.sub.2 and Ta.sub.2 O.sub.5 in the following weight ratio against the base composition;0<MnO.sub.2 .ltoreq.0.5 wt. %0<Ta.sub.2 O.sub.5 .ltoreq.1.2 wt.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: April 18, 1995
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuhiko Michiura, Hiroshi Tamura
  • Patent number: 5403788
    Abstract: A dielectric ceramic composite material comprising a dielectric ceramics and a glass having a softening temperature lower than the sintering temperature of the dielectric ceramics, wherein said particles of the dielectric ceramics are randomly dispersed in a matrix of the glass. This composite material can be formed by molding a mixture of the dielectric ceramics powder and glass powder at first, and by firing this mold (including a film thereof) at the softening temperature of the glass or higher. The obtained dielectric ceramics composite material can be extensively utilized as various ceramic functional elements or electronic components incorporated in various piezoelectric, pyroelectric, ferroelectric memory, actuator elements and many others.
    Type: Grant
    Filed: April 21, 1994
    Date of Patent: April 4, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masamitsu Nishida, Koichi Kugimiya
  • Patent number: 5401695
    Abstract: A method for improving the properties of ceramic green bodies is provided. In particular, ceramic green bodies having improved green strength are provided. Incorporating certain acid-containing polymers as binders at a level of at least about 1 to about 15, preferably at least about 3 to about 10 percent by weight based on the weight of ceramic particles improves the green strength of the resulting ceramic green bodies.
    Type: Grant
    Filed: January 24, 1994
    Date of Patent: March 28, 1995
    Assignee: Rohm and Haas Company
    Inventor: Xianliang Wu
  • Patent number: 5378663
    Abstract: A dielectric ceramic composition is disclosed which includes: a main ceramic composition of barium oxide and titanium oxide, or barium oxide, titanium oxide and at least one of strontium oxide, calcium oxide, zirconia and zinc oxide, which composition is represented by (1-a-b)BaO.multidot.aSrO.multidot.bCaO.multidot.x[(1-c)TiO.sub.2 .multidot.cZrO.sub.2 ].multidot.yZnO, where 3.1.ltoreq.x .ltoreq.5.4, 0.ltoreq.y.ltoreq.2.9, 0.ltoreq.a+b.ltoreq.0.4, 0.ltoreq.c.ltoreq.0.2; and a secondary component at least a part of which consists of a B.sub.2 O.sub.3 material or a glass material containing B.sub.2 O.sub.3 as one of glass components, the secondary component being added to the main ceramic composition, in an amount of 0.1-7.5 parts by weight of B.sub.2 O.sub.3 per 100 parts by weight of the main ceramic composition.
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: January 3, 1995
    Assignee: NGK Insulators, Ltd.
    Inventors: Masahiro Abe, Tatsumi Sugiura, Tsutomu Nanataki, Shinsuke Yano
  • Patent number: 5376603
    Abstract: In a dielectric ceramic composed of a La.sub.2 O.sub.3 -CaO-TiO.sub.2 -MgO type or a BaO-Nd.sub.2 O.sub.3 -TiO.sub.2 type, the oxygen vacancy concentration of the ceramic is controlled below 7.times.10.sup.18 /cm.sup.3 by, for example, annealing the mixture after firing, or heat-treating the mixture after firing. The Q value of the dielectric ceramic can be markedly increased. In addition, ceramics having stable properties can be produced. Thus, the dielectric ceramics can fully cope with high frequencies and large electrification.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: December 27, 1994
    Assignee: Kyocera Corporation
    Inventors: Seiichiro Hirahara, Nobuyoshi Fujikawa
  • Patent number: 5368834
    Abstract: Titanate ceramic materials are made by forming a common solution (10) of barium acetate, strontium acetate, isopropyl titanate, lactic acid and water, forming a mist of particles of approximately 50 um or smaller, directing a carrier stream of gas (14) through the mist into a reaction zone in a furnace (20) where the material is pyrolyzed and then collected as a powder in a filter (24) or deposited onto a substrate. The tetra-isopropyl titanate and lactic acid may be replaced by commercially available titanium ammonium lactate. In a first embodiment the carrier gas is an oxidizing gas while in a second embodiment it is an inert gas resulting in powder having greater density.
    Type: Grant
    Filed: August 13, 1993
    Date of Patent: November 29, 1994
    Assignee: Texas Instruments Incorporated
    Inventors: Bernard M. Kulwicki, David F. Lynch, Stanley J. Lukasiewicz
  • Patent number: 5369068
    Abstract: Disclosed is a bismuth layer compound expressed by a chemical formula, (M1.sub.1-2x M2.sub.x Bi.sub.4+x)Ti.sub.4 O.sub.15, wherein "M1" is alkaline earth metal including Sr at least, "M2" is alkali metal, and "x" falls in a range, 0.06.ltoreq.x.ltoreq.0.44. "M1" can be replaced by Pb or combinations of Pb and alkaline earth metal. The bismuth layer compound exhibits a less fluctuating sensitivity with respect to temperature variations. The bismuth layer compound can further include Mn in a form of MnO in an amount of from 0.02 to 0.25% by weight, and thereby it exhibits not only an upgraded sensitivity but also it does not exhibits a hysteresis in a force-electric charge output diagram.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: November 29, 1994
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Kazuhide Kaneko
  • Patent number: 5362693
    Abstract: The present invention provides ceramic compositions for preparing multi-layer capacitors (MLCs) having high dielectric constants between about 3000 and 4700 and stable temperature coefficients (TC) prepared from high purity barium titanate, niobium pentoxide, and cobalt oxide.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: November 8, 1994
    Assignee: Tam Ceramics, Inc.
    Inventors: Mike S. H. Chu, Susan E. Corah
  • Patent number: 5362472
    Abstract: A method describing the manufacture and use of aqueous suspensions comprising fine-powdered ceramic solid particles, dispersing agents and, if necessary, binders, in which method the manufacture of the suspensions includes the following process steps which are carried out separately or in combination:washing the solid particles in water before preparing the suspension;adding anionic compounds, in the form of sulphates, carbonates, iodates, chromates, oxalates, citrates and/or tartrates;manufacturing the suspensions and/or storing the finished suspensions in a CO.sub.2 -free gaseous atmosphere;manufacturing the suspensions and storing the finished suspensions at a temperature below 20.degree. C., preferably below 15.degree. C.;adding additional dispersing agents to the suspension at a time when reagglomeration of the solid particles in the suspension has not yet started or just started.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: November 8, 1994
    Assignee: U.S. Philips Corporation
    Inventors: Josef Lauter, Walter Mayr, Joachim Opitz, Gerd Romanowski
  • Patent number: 5337209
    Abstract: A dielectric ceramic composition is disclosed comprising lead magnesium niobate and strontium titanate, barium titanate or a combination thereof. Dopants such as Ta, La, Y, Eu, Nd, Sm, Gd, W, Si, Zr and Sb may also be included in the composition. The lead magnesium niobate with strontium titanate and/or barium titanate composition has been found to possess extremely favorable properties such as high dielectric constant, low dielectric loss, high breakdown strength, low field-induced strain, high electrical resistivity and exceptionally high energy storage capacity. A process is also disclosed for the production of dielectric ceramic materials which includes the use of hot isostatic pressing in an oxygen-containing atmosphere. The disclosed dielectric compositions are useful in capacitors for many applications, including medical devices such as defibrillators and pacemakers.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: August 9, 1994
    Assignee: Martin Marietta Corporation
    Inventors: Audrey E. Sutherland, Keith Bridger, Eric M. Fiore, Julie A. Christodoulou, Alex E. Bailey, Allan S. Gelb
  • Patent number: 5335139
    Abstract: A multilayer ceramic chip capacitor includes alternately stacked dielectric layers and internal electrode layers. The dielectric layers contain barium titanate as a major component and magnesium oxide, manganese oxide, barium oxide and/or calcium oxide, silicon oxide and optionally, yttrium oxide as minor components in such a proportion that there are present 0.1-3 mol of MgO, 0.05-1.0 mol of MnO, 2-12 mol of BaO+CaO, 2-12 mol of SiO.sub.2 and up to 1 mol of Y.sub.2 O.sub.3 per 100 mol of BaTiO.sub.3. The capacitor satisfies the standard temperature dependence of capacitance and shows a minimized change of capacitance with time under an applied DC electric field and a long insulation resistance life. Where the dielectric layers contain 0.1-3 mol of MgO, 1-5 mol of Y.sub.2 O.sub.3, 2-12 mol of BaO+CaO, and 2-12 mol of SiO.sub.2 per 100 mol of BaTiO.sub.3, the capacitor shows improved DC bias performance.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: August 2, 1994
    Assignee: TDK Corporation
    Inventors: Takeshi Nomura, Yukie Nakano, Akira Satoh, Tomohiro Arashi
  • Patent number: 5328718
    Abstract: A thin film of barium titanate is formed on a substrate by immersing the substrate in an aqueous solution containing barium ions and titanium alkoxide. The aqueous solution may contain not more than 20 vol % of one or more alkanolamines expressed by the general formula:HO(C.sub.n H.sub.2n)mNH.sub.3-mwhere n is not more than 10, and m=1, 2 or 3.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: July 12, 1994
    Assignee: Myrata Mfg., Co., Ltd.
    Inventors: Yoshio Abe, Yukio Hamaji, Yukio Sakabe
  • Patent number: 5322828
    Abstract: A non-reducible dielectric ceramic composition consists essentially of a main component consisting essentially of oxides of BaO, CaO, MgO, TiO.sub.2, ZrO.sub.2 and Nb.sub.2 O.sub.5 and having a composition expressd by the general formula:{(Ba.sub.1-x-y Ca.sub.x Mg.sub.y)O}.sub.m (Ti.sub.1-o-p Zr.sub.o Nb.sub.p)O.sub.2+p/2wherein 0<x.ltoreq.0.20, 0<y.ltoreq.0.05, 0<o.ltoreq.0.25, 0.0005.ltoreq.p .ltoreq.0.023, and 1.000.ltoreq.m.ltoreq.1.03; at least one primary additive selected from the group consisting of oxides of Mn, Fe, Cr, Co and Ni; and at least one secondary additive selected from the group consisting of SiO.sub.2 and ZnO. The primary additives contained in an mount of 0.02 to 2.0 moles per 100 moles of the main component in terms of respective oxides, MnO.sub.2, Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, CoO and NiO, while the secondary additive is contained in an amount of 0.1 to 2.0 moles per 100 moles of the main component.
    Type: Grant
    Filed: October 19, 1993
    Date of Patent: June 21, 1994
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Harunobu Sano, Yukio Hamaji, Kunisaburo Tomono
  • Patent number: 5322821
    Abstract: Ceramic beads having a bimodal pore distribution are prepared by a process involving a) formation of a ceramic particle slurry, b) adding a foamable prepolymer to the slurry to form a mixture, c) dispersing the mixture as beads in a second liquid, d) polymerizing and foaming the prepolymer, e) recovering the beads and firing them to remove the polymer and bond the ceramic particles. The beads can optionally be joined by sintering. Beads with a monodal pore distribution can be made by using a nonfoaming prepolymer.
    Type: Grant
    Filed: August 23, 1993
    Date of Patent: June 21, 1994
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Rasto Brezny
  • Patent number: 5319517
    Abstract: The invention provides a multilayer ceramic chip capacitor having internal electrodes and dielectric layers, wherein a dielectric material containing a dielectric oxide having a composition of the following formula:[(Ba.sub.1-x-y Ca.sub.x Sr.sub.y)O].sub.m (Ti.sub.1-z Zr.sub.z)O.sub.2wherein 0.ltoreq.x.ltoreq.0.25, 0.ltoreq.y.ltoreq.0.05, 0.1.ltoreq.z.ltoreq.0.3, and 1.000.ltoreq.m.ltoreq.1.020 and having added thereto an oxide of Mn and/or a compound which converts to the oxide upon firing in an amount of 0.01 to 0.5% by weight calculated as oxide (MnO), an oxide of Y and/or a compound which converts to the oxide upon firing in an amount of 0.05 to 0.5% by weight calculated as oxide (Y.sub.2 O.sub.3), an oxide of V and/or a compound which converts to the oxide upon firing in an amount of 0.005 to 0.3% by weight calculated as oxide (V.sub.2 O.sub.5), and an oxide of W and/or a compound which converts to the oxide upon firing in an amount of 0.005 to 0.3% by weight calculated as oxide (WO.sub.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: June 7, 1994
    Assignee: TDK Corporation
    Inventors: Takeshi Nomura, Yukie Nakano, Akira Satoh, Atsushi Hitomi
  • Patent number: 5314651
    Abstract: An improved pyroelectric material comprises a polycrystalline material doped with at least one donor element such that the polycrystalline material has a grain size less than 10 .mu.m (or 5 .mu.m) and a Figure of Merit greater than 90 nC/(cm.sup.2.K). In the preferred embodiments the polycrystalline material is barium strontium titanate or calcium-substituted barium strontium titanate. The donor element may be Nb, Ta, Bi, Sb, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er or a combination thereof. The material may additionally be doped with an acceptor such as Co, Cu, Fe, Mn, Ru, Al, Ga, Mg, Sc, K, Na, U, In, Mg, Ni, Yb or a combination thereof to control the resistivity. Other structures and methods are also disclosed.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: May 24, 1994
    Assignee: Texas Instruments Incorporated
    Inventor: Bernard M. Kulwicki
  • Patent number: 5312790
    Abstract: A novel ceramic ferroelectric material having a low dielectric constant, loss and high tunability. The material is a composite comprising Barium Strontium Titanate (BSTO) and a ceramic material having a low dielectric constant. The preferred composite is represented by Ba.sub.1-x Sr.sub.x TiO.sub.3 -Al.sub.2 O.sub.3, wherein x is greater than 0.00, but less than or equal to 0.70, and wherein the percent weight ratio between Ba.sub.1-x Sr.sub.x TiO.sub.3 and Al.sub.2 O.sub.3 ranges from approximately 99%-40% and 1%-60%, respectively. The novel materials possess superior electronic properties; and they may be employed in various antenna systems.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: May 17, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Louise C. Sengupta, Eric Ngo, Steven Stowell, Gary Gilde, Robert Lancto
  • Patent number: 5310709
    Abstract: A nonreducible dielectric ceramic composition of a system, (A.sub.1-x R.sub.x).sub.y BO.sub.3, is produced using using at least one compound selected from the group consisting of water-soluble inorganic compounds and organic solvent-soluble organometallic compounds of rare earth element R together with oxides and/or carbonates of elements A and B.
    Type: Grant
    Filed: February 14, 1992
    Date of Patent: May 10, 1994
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Wada, Yoshiaki Kohno
  • Patent number: 5310710
    Abstract: A dielectric ceramic composition which comprises a composition represented by xBaO.yNd.sub.2 O.sub.3.zTiO.sub.2 (where 8.5.ltoreq.x.ltoreq.20, 5.ltoreq.y.ltoreq.23, 62.ltoreq.z.ltoreq.85, and x+y+z=100), Y.sub.2 O.sub.3 in an amount not more than 15 wt % of the amount of said composition, and Al.sub.2 O.sub.3 in an amount not more than 2 wt % of the total amount of the principal components BaO, Nd.sub.2 O.sub.3, TiO.sub.2, and Y.sub.2 O.sub.3. And a relative permittivity .epsilon.r of the dielectric ceramic is not less than 59, its dielectric loss (tan .delta.) is 3.times.10.sup.-4 .about.8.times.10.sup.-4 (2.7 GHz), and its temperature coefficient of resonant frequency .tau.f may be -30.about.+10 ppm/.degree.C. This microwave ceramic dielectric will be used for dielectric resonators in the microwave frequency region, microwave IC substrates, and impedance matching of microwave circuits.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: May 10, 1994
    Assignee: NGK Spark Plug Company, Ltd.
    Inventors: Masanori Takase, Hirofumi Ozeki
  • Patent number: 5296426
    Abstract: A composition for forming a densified ceramic dielectric body, the composition consisting essentially of (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f)0-0.1 wt. % manganese oxide or precursor thereof. This composition can be used to form the dielectric layers in multilayer electrical devices such as circuits and capacitors.
    Type: Grant
    Filed: July 20, 1992
    Date of Patent: March 22, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Ian Burn