Barium Titanate Patents (Class 501/137)
  • Patent number: 6426018
    Abstract: The present invention provides a piezoelectric ceramic composition which contains no lead and has piezoelectric characteristics suitable for practical use. The piezoelectric ceramic composition has a complex perovskite structure represented by the formula: (1−x−y−z)BaTiO3-x(Bi1/2Na1/2)TiO3-yCaTiO3-zBa (Zn1/3Nb2/3)O3 and comprises Ba, Ti, O, Bi, Na, Ca, Zn and Nb in the proportion satisfying the following conditions of x, y and z: 0.0<x≦0.90, 0.0≦y≦0.20, and 0.0≦z≦0.05.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: July 30, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichi Takahashi, Masamitsu Nishida
  • Patent number: 6426017
    Abstract: The piezoelectric ceramic composition of the present invention contains, as a main component, a material having a composition represented by Formula: CaMXBi4−xTi4−X(Nb1−ATaA)XO15, where M is at least one element selected from the group consisting of Ca, Sr, and Ba; 0.0≦A≦1.0; and 0.0≦X≦0.6.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: July 30, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichi Takahashi, Masamitsu Nishida, Hiroshi Sogou
  • Publication number: 20020098968
    Abstract: The present invention provides a piezoelectric ceramic composition which contains no lead and has piezoelectric characteristics suitable for practical use.
    Type: Application
    Filed: November 20, 2001
    Publication date: July 25, 2002
    Inventors: Keiichi Takahashi, Masamitsu Nishida
  • Publication number: 20020098969
    Abstract: Provided is a dielectric ceramic composition suitably used for forming dielectric ceramic layers which constitute a laminated ceramic capacitor obtained by firing in a reducing atmosphere. Even when the dielectric ceramic composition is formed into thin dielectric ceramic layers, a highly reliable laminated ceramic capacitor having a small temperature coefficient of capacitance, a long lifetime under high temperature and high pressure conditions, and a small change in electrostatic capacitance with time under a DC voltage application can be realized. The dielectric ceramic composition contains a primary component, an additive component, and an auxiliary sintering agent, wherein the primary component and the additive component are represented by the formula 100BaTiO3+a{(1−b)R+bV}+cM, and 1.25≦a≦8.0, 0<b≦0.2, 1.0<c≦6.0, and a/c>1.1 are satisfied.
    Type: Application
    Filed: November 5, 2001
    Publication date: July 25, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Tomoyuki Nakamura, Kotaro Hata, Harunobu Sano
  • Publication number: 20020091059
    Abstract: Coated barium titanate-based particles and a process to coat the particles are provided. The coating includes a dopant metal compound that is insoluble in water under alkaline conditions. The dopant metal in the coating is selected from the group of metals which form oxides or hydroxides that are soluble in water under alkaline conditions such as tungsten, molybdenum, vanadium, and chromium. The process involves precipitating the insoluble compound from an aqueous medium as a coating on surfaces of barium titanate-based particles. The coated barium titanate-based particles may be further processed, for example, to form dielectric materials which may be used in many electronic applications such as in MLCCs applications.
    Type: Application
    Filed: January 10, 2001
    Publication date: July 11, 2002
    Inventors: Sridhar Venigalla, Kathleen A. Thrush
  • Patent number: 6411495
    Abstract: The present invention provides a dielectric ceramic composition whose electrostatic capacity has an excellently low temperature dependence; which can be fired in a reducing atmosphere; and which is advantageously used in a laminated ceramic capacitor having an internal electrode formed of a base metal such as nickel or nickel alloy. The dielectric ceramic composition is represented by the following formula: {Ba1-xCaxO}mTiO2+&agr;MgO+&bgr;MnO, wherein 0.001≦&agr;≦0.05; 0.001≦&bgr;≦0.025; 1.000<m≦1.035; and 0.02≦x≦0.15.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: June 25, 2002
    Assignee: Murata Manufacturing Co. Ltd.
    Inventors: Nobuyuki Wada, Jun Ikeda, Takashi Hiramatsu, Yukio Hamaji
  • Patent number: 6407024
    Abstract: A dielectric composition containing at least calcium titanate, strontium titanate, and barium titanate, wherein at least the molar ratios of composition of the three are such that the molar ratio of composition (P) of calcium titanate is 0.5 to 0.85, the molar ratio of composition (Q) of strontium titanate is 0.05 to 0.4, and the molar ratio of composition (R) of barium titanate is 0.1 to 0.2 (where, P+Q+R=1).
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: June 18, 2002
    Assignee: TDK Corporation
    Inventors: Shigeki Satoh, Yoshinori Fujikawa, Akiko Nagai, Kaori Masumiya
  • Publication number: 20020072464
    Abstract: A dielectric ceramic includes ABO3 as a major component and R and M as accessory components, where A is at least one of Ba, Sr and Ca; B is at least one of Ti, Zr and Hf; R is at least one of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and M is at least one of Ni, Co, Fe, Cr and Mn. The dielectric ceramic contains the components R and M at about 70% or more of analysis points in grain boundaries. This dielectric ceramic is suitable for use in dielectric ceramic layers of a multilayer ceramic capacitor obtained by firing in a reducing atmosphere, has a long life at high temperatures and high voltages, exhibits less time-dependent change in electrostatic capacity under application of a direct-current voltage and has satisfactory reliability even when its thickness is reduced.
    Type: Application
    Filed: October 18, 2001
    Publication date: June 13, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Tomoyuki Nakamura, Kentaro Sakai, Harunobu Sano
  • Patent number: 6403513
    Abstract: A dielectric ceramic composition comprising a main component of composed mainly of barium titanate, a first subcomponent including at least one compound selected from MgO, CaO, BaO, SrO and Cr2O3, a second subcomponent containing silicone oxide as a main composition, a third subcomponent including at least one compound selected from V2O5, MoO3, and WO3, a fourth subcomponent including an oxide of R1 (where R1 is at least one element selected from Sc, Er, Tm, Yb, and Lu), and a fifth subcomponent including CaZrO3 or CaO+ZrO2, wherein the ratios of the subcomponents to 100 moles of the main component of composed mainly of barium titanate are the first subcomponent of 0.1 to 3 moles, the second subcomponent of 2 to 10 moles, the third subcomponent of 0.01 to 0.5 moles, the fourth subcomponent of 0.5 to 7 moles (where the number of moles of the fourth subcomponent is the ratio of R1 alone), and the fifth subcomponent of 0<fifth subcomponent≦5 moles.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: June 11, 2002
    Assignee: TDK Corporation
    Inventors: Shigeki Sato, Yoshinori Fujikawa, Yoshihiro Terada
  • Patent number: 6399529
    Abstract: An electric-field-inducible deformable porcelain material is provided, comprising a main component BaTiO3, with 0.05 to 2 wt % of at least one selected from Mn, Cu and Co in terms of a metal added thereto. The crystal phase in the porcelain is a single perovskite phase, and the value of the transversal electric-field-inducible deformation is 300×10−6 or more in the field strength of 2000 V/mm. It is presumed that the amount of the rotating 90° domain becomes greater, and the electric-field-induced deformation due to this is increased. Thus, a sufficient displacement amount as a piezoelectric material is obtained.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: June 4, 2002
    Assignee: NGK Insulators, Ltd.
    Inventors: Hirofumi Yamaguchi, Toshikatsu Kashiwaya
  • Patent number: 6396681
    Abstract: A nonreducing dielectric contains a main-component having a perovskite crystal phase and satisfying the formula (Ca1-a-b-cSraBabMgc)m(Zr1-w-x-y-zTiwMnxNiyHfz)O3 and a compound oxide represented by the formulae (Si, T)O2—MO—XO and (Si, T)O2—(Mn, M′)O—Al2O3. The ratio of the intensity of the maximum peak of a crystal phase not of the perovskite crystal phase to the intensity of the maximum peak assigned to the perovskite crystal phase appearing at 2&thgr;=25 to 35° is about 5% or less in a CuK&agr; X-ray diffraction pattern.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: May 28, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Masahiro Naito, Tomoo Motoki, Harunobu Sano
  • Patent number: 6385035
    Abstract: A dielectric ceramic composition comprises 100 parts by weight of a primary constituent, about 0.1 to 25 parts by weight of a first secondary constituent comprising a SiO2-based glass not containing lead oxide, and about 20 parts by weight or less of a second secondary constituent comprising manganese oxide (MnO). The primary constituent is represented by the formula x(Ba&agr;Ca&bgr;Sr&ggr;)O-y[(TiO2)1−m(ZrO2)m]-zRe2O3 wherein x+y+z=100 on a molar basis, &agr;+&bgr;+&ggr;=1, 0≦&bgr;+&ggr;≦0.8, 0<m<0.15, and Re is at least one rare earth element. The mole fraction (x, y, z) of (Ba&agr;Ca&bgr;Sr&ggr;)O, (TiO2)1−m(ZrO2)m, and Re2O3 lies within a range surrounded by points in a ternary diagram, depending on the content of the ceramic capacitors. The dielectric ceramic composition can be sintered at low temperatures and exhibits a high specific dielectric constant and a high Q value.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: May 7, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroaki Matoba, Harunobu Sano
  • Patent number: 6380118
    Abstract: A nonlinear dielectric ceramic having the D-E hysteresis characteristics contains a barium titanate-based compound as a principal constituent and a nonreducing oxide glass as a secondary constituent, and thus the nonlinear dielectric ceramic has reduction resistance. A pulse generating capacitor including the nonlinear dielectric ceramic, a high-pressure vapor discharge lamp circuit including the pulse generating capacitor, and a high-pressure vapor discharge lamp including the pulse generating capacitor are also disclosed.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: April 30, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kazuhiro Harada, Harunobu Sano
  • Patent number: 6376079
    Abstract: The present invention provides a semiconducting ceramic which possesses a dielectric strength of 800 V/mm or more and a specific resistance at room temperature of 100 &OHgr;·cm or less, the specific resistance at room temperature undergoing substantially no time-course change. The semiconducting ceramic is formed of a sintered semiconducting material containing barium titanate, wherein the average grain size of the semiconducting ceramic is about 1.0 &mgr;m or less and the relative spectral intensity ratio represented by BaCO3/BaO, which is determined by XPS at the surface of the ceramic, is 0.5 or less.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: April 23, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Mitsutoshi Kawamoto, Hideaki Niimi
  • Publication number: 20020045533
    Abstract: A dielectric composition containing at least calcium titanate, strontium titanate, and barium titanate, wherein at least the molar ratios of composition of the three are such that the molar ratio of composition (P) of calcium titanate is 0.5 to 0.85, the molar ratio of composition (Q) of strontium titanate is 0.05 to 0.4, and the molar ratio of composition (R) of barium titanate is 0.1 to 0.2 (where, P+Q+R=1).
    Type: Application
    Filed: October 5, 2001
    Publication date: April 18, 2002
    Applicant: TDK CORPORATION
    Inventors: Shigeki Satoh, Yoshinori Fujikawa, Akiko Nagai, Kaori Masumiya
  • Publication number: 20020034667
    Abstract: Electronically tunable thick film composites of tunable phases such as barium strontium titanate and additional dielectric oxide phases are disclosed. The composite thick films can contain multiple phases such as barium strontium titanate and MgTiO3, Mg2SiO4, CaSiO3, MgO, MgZrO3, CaTiO3, MgAl2O4, and MgSrZrTiO6. The thick films may contain further additives such as zirconnates, stannates, rare earths, niobates and tantalates, for example, CaZrO3, BaZrO3, SrZrO3, BaSnO3, CaSnO3, MgSnO3, Bi2O3/2SnO2, Nd2O3, Pr7O11, Yb2O3, Ho2O3, La2O3, MgNb2O6, SrNb2O6, BaNb2O6, MgTa2O6, BaTa2O6, and Ta2O3 to improve the electronic and microwave properties of the thick film composites. The particle size of these films may be controlled in order to optimize the electronic and microwave properties. The electronically tunable thick film composites may be made by techniques such as screen-printing or spray deposition.
    Type: Application
    Filed: June 15, 2001
    Publication date: March 21, 2002
    Inventor: Louise C. Sengupta
  • Patent number: 6359327
    Abstract: A monolithic electronic element is fabricated from a semiconducting ceramic, which element can be produced through firing at 1000° C. or lower and exhibits a satisfactory PTC characteristic even when the element is produced through reoxidation at low temperature. The monolithic electronic element 1 includes a sintered laminate 3 formed of alternatingly stacked semiconducting ceramic layers 5 and internal electrode layers 7, and external electrodes 9 formed on the sintered laminate, wherein the semiconducting ceramic layers 5 comprise sintered barium titanate containing boron oxide; an oxide of at least one metal selected from among barium, strontium, calcium, lead, yttrium and a rare earth element; the boron oxide being incorporated in an amount, as reduced to atomic boron (B), satisfying the following relationships: 0.001≦B/&bgr;≦0.50 and 0.5≦B/(&agr;−&bgr;)≦10.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: March 19, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hideaki Niimi, Tatsuya Matsunaga
  • Patent number: 6355097
    Abstract: Bis(dipivaloylmethanato)diisobutoxytitanium or bis(dipivaloylmethanato)-di(2,2 -dimethyl-1-propoxytitanium per se, or as used as a raw material in a MOCVD process, as is or as a solution in an organic solvent, for example, tetrahydrofuran, produces a dielectric thin film of a fine texture having a film thickness which is proportional to the deposition time and the concentration of the solution.
    Type: Grant
    Filed: May 16, 2001
    Date of Patent: March 12, 2002
    Assignee: Mitsubishi Materials Corporation
    Inventors: Atsushi Itsuki, Taiji Tachibana, Hiroto Uchida, Katsumi Ogi
  • Patent number: 6346496
    Abstract: A ceramic for the PTC thermistor having a resistivity at room temperature of 5 &OHgr;·cm or less, static withstanding voltage of 60 V/mm or more and temperature resistance coefficient of 9.0 %/° C., having small dispersion of the resistance, is composed of principal components of about 30 to 97 mol % of BaTiO3, about 1 to 50 mol % of PbTiO3, about 1 to 30 mol % of SrTiO3 and about 1 to 25 mol % of CaTiO3 (the total content of them being 100 mol %), as well as about 0.1 to 0.3 mole of Sm, about 0.01 to 0.03 mole of Mn and 0 to about 2.0 mole of Si relative to 100 moles of the principal components, the composite material being preferably heat-treated in an oxidative atmosphere after being fired in a reducing or neutral atmosphere for obtaining the ceramic.
    Type: Grant
    Filed: July 23, 1999
    Date of Patent: February 12, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yasuhiro Nabika, Tetsukazu Okamoto, Toshiharu Hirota, Noriyuki Yamamoto
  • Publication number: 20020016249
    Abstract: A ceramic capacitor containing at least one dielectric layer formed from a dielectric ceramic composition comprising a sintered body containing ceramic particles having a core/shell structure in an amount of 15% or more based on the total ceramic particles of the sintered body, the core/shell structured particle being composed of a core portion, which is BaTiO3 crystal, and a shell portion surrounding the core portion, which is made of a solid solution comprising BaTiO3 as a major component, has excellent temperature characteristics and a long life-time.
    Type: Application
    Filed: June 29, 2001
    Publication date: February 7, 2002
    Inventors: Kenji Saito, Koichiro Morita, Youichi Mizuno, Yasunobu Kawamoto, Yoshikazu Okino, Noriyuki Kohzu, Hirokazu Chazono
  • Publication number: 20020016246
    Abstract: The present invention provides a dielectric ceramic composition, a capacitor using the composition and the producing method, of having a lower dielectric loss and a stable characteristics in high frequency bandwidth, and enabling to use a base metal or a carbon-based material as an electrode material by allowing sintering at a low temperate, thereby resulting in lower cost.
    Type: Application
    Filed: March 30, 2001
    Publication date: February 7, 2002
    Inventors: Jong Hee Kim, Shigehiro Fujino, Nobutake Hirai
  • Patent number: 6335302
    Abstract: A dielectric composition containing at least calcium titanate, strontium titanate, and barium titanate, wherein at least the molar ratios of composition of the three are such that the molar ratio of composition (P) of calcium titanate is 0.5 to 0.85, the molar ratio of composition (Q) of strontium titanate is 0.05 to 0.4, and the molar ratio of composition (R) of barium titanate is 0.1 to 0.2 (where, P+Q+R=1).
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: January 1, 2002
    Assignee: TDK Corporation
    Inventors: Shigeki Satoh, Yoshinori Fujikawa, Akiko Nagai, Kaori Masumiya
  • Publication number: 20010046933
    Abstract: Sol-gel-derived “0-3 composite” ceramics are provided for application to electronics components directly written onto low-temperature substrates. The 0-3 composite materials are prepared from a mixture of liquid-phase and solid-phase constituents, as are the pastes conventionally used to prepare thick-film materials for the electronics industry. The prepared 0-3 composites exhibit several advantages, including substantial reductions in (1) processing temperatures, (2) solvent concentrations, and (3) organic post-processing-residual concentrations. In addition, the rapid removal of solvent during application is compatible with such rapid prototyping methods as laser densification. The 0-3 composites may be deposited onto plastic substrates while still meeting expected performance standards. Therefore, the direct writing of electronics components onto such low-temperature substrates as plastic may be achieved using sol-gel-based 0-3 composites.
    Type: Application
    Filed: February 7, 2001
    Publication date: November 29, 2001
    Inventors: Robert L. Parkhill, Steven M. Coleman, Edward T. Knobbe
  • Patent number: 6319871
    Abstract: Disclosed is a dielectric material comprising: a main ingredient having a composition represented by xBaO-yRE2O3-zTiO2, wherein RE represents at least one rare earth element, and x+y+z=100 mol %; at least one alkali metal oxide; and an ingredient derived from an oxygen supplying agent which releases oxygen on heating.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: November 20, 2001
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Motohiko Sato, Hitoshi Yokoi, Kazushige Ohbayashi
  • Patent number: 6316376
    Abstract: A dielectric ceramic composition comprising 3BaO.5TiO2.3Nb2O5 (Ba3Ti5Nb6O28) as a main component and at least one selected from, as a minor component, (b-1) sintering auxiliary selected from the group consisting of a boron-containing glass compound, CuO, ZnO or mixtures thereof, or (b-2) additives selected from the group consisting of V2O5, SnO2, MgO, NiO, Sb2O3, Bi2O3, LiF, Ag2O or mixtures thereof, and mixtures of (b-1) and (b-2), and its preparation process are disclosed.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: November 13, 2001
    Inventors: Kug Sun Hong, Jung-Kun Lee, Dong-Wan Kim, Hyun-Seok Jung, Hee-Bum Hong, Jae-Yun Lee, Soung-Jun Yoon
  • Patent number: 6304157
    Abstract: A high-frequency dielectric ceramic composition comprises Ba, Ti, Nd, Sm, and Pr as primary components represented by the formula xBaO-yTiO2-z{(1−m−n)Nd2O3-mSm2O3-nPr2O11/3} wherein coefficients x, y, z, m, and n represent molar ratios, x+y+z=1, 0<m≦0.40, 0<n≦0.25, and the coefficients x, y, and z are in an area bounded by points A, B, C and D in a ternary diagram, wherein point A is at (x=0.16, y=0.70, z=0.14), point B is at (x=0.16, y=0.68, z=0.16), point C is at (x=0.13, y=0.68, z=0.19), and point D is at (x=0.13, y=0.70, z=0.17); wherein the composition further comprises a Bi compound in an amount of more than 0 parts by weight to about 9 parts by weight on the basis of Bi2O3 and an Fe compound in an amount of more than 0 parts by weight to about 0.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: October 16, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takaya Wada, Hiroshi Tamura
  • Patent number: 6303529
    Abstract: A dielectric ceramic which exhibits small variation in dielectric constant, allows use of a base metal, can be fired in a reducing atmosphere and which is suitable for constituting a dielectric ceramic layer for, e.g., a laminated ceramic capacitor is obtained by firing barium titanate powder in which the c-axis/a-axis ratio in the perovskite structure is about 1.000 or more and less than about 1.003 and the amount of OH groups in the crystal lattice is about 2.0 wt. % or less. The barium titanate powder starting material preferably has a maximum particle size of about 0.3 &mgr;m or less and an average particle size of about 0.05-0.15 &mgr;m. Each particle of the barium titanate powder preferably comprises a low-crystallinity portion and a high-crystallinity portion, the diameter of the low-crystallinity portion being about 0.5 times or more the particle size of the powder.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: October 16, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Wada, Takashi Hiramatsu, Jun Ikeda, Yukio Hamaji
  • Publication number: 20010026865
    Abstract: An oxide having a perovskite structure, for example, barium titanate, is provided in which the particle diameter is as small as about 0.03 to 0.2 &mgr;m, the amount of OH groups in the crystal lattice is less than about 0.2% by weight, the c/a axial ratio is as large as about 1.0033 or more and sufficient ferroelectricity is exhibited. Barium titanate is produced with steps of mixing a BaCO3 powder and a TiO2 powder having a specific surface area of about 10 m2/g or more and heat-treating the mixed powder. In the heat treatment, in the case in which a partial pressure of oxygen is decreased to about 2×103 Pa or less and more than about 2×102 Pa, the heat treatment is performed at a temperature within the range of about 700 to 1100° C., and in the case in which a partial pressure of oxygen is decreased to about 2×102 Pa or less, the heat treatment is performed at a temperature within the range of about 600 to 1100° C.
    Type: Application
    Filed: March 1, 2001
    Publication date: October 4, 2001
    Applicant: Murata Manufacturing Co., Ltd.
    Inventor: Toshiyuki Miyoshi
  • Patent number: 6295196
    Abstract: A monolithic ceramic electronic component includes a laminate including a plurality of ceramic layers obtained by sintering a ceramic raw material powder, and a plurality of internal electrodes located between the ceramic layers and obtained by sintering a metallic powder. The ceramic layers have a thickness of about 3 &mgr;m or less and are composed of ceramic grains having an average particle diameter of more than about 0.5 &mgr;m, the particle diameter of the ceramic grains in the thickness direction of the ceramic layers is smaller than the thickness of the ceramic layers, and the internal electrodes have a thickness of about 0.2 to 0.7 &mgr;m.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: September 25, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yukio Hamaji, Nobuyuki Wada, Tsuyoshi Yamana, Takanori Nakamura
  • Publication number: 20010018989
    Abstract: The invention presents an ion conductor with high reliability, that is one of the following perovskite oxides: {circle over (1)} perovskite oxide of the composition BaZr1-xCexO3-p (0<x<0.8); {circle over (2)} perovskite oxide consisting essentially of Ba, Zr, Ce and O, and substantially conducting protons only; {circle over (3)} perovskite oxide of the composition BaZr1-x-yCexMyO3-p (M, O≦x<1,0<y<1, x+y<1) that is a single-phase polycrystal of cubic, tetragonal or orthorhombic crystal structure whose unit cell edges a, b and c (with a≧b≧c) satisfy 0.8386 nm<a<0.8916 nm and b/a≧0.90; {circle over (4)} perovskite oxide of the same composition as in {circle over (3)} that is a single-phase sintered product with a density of at least 96% of the theoretical density; and {circle over (5)} perovskite oxide of the same composition as in {circle over (3)} that is a single-phase sintered product with 1 to 30 &mgr;m granular diameter.
    Type: Application
    Filed: February 7, 2001
    Publication date: September 6, 2001
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventor: Noboru Taniguchi
  • Patent number: 6284216
    Abstract: A barium titanate powder has an average particle size ranging from 0.1-1.0 &mgr;m, a CV value (standard deviation of the particle size/the average particle size) of the particle size distribution being 40% or less, and a zeta-potential ranging from −30 to −60 mV measured by a laser Doppler method using electrophoresis at pH 6.4. The barium titanate powder is presintered at a temperature ranging from 900 to 1200° C. The barium titanate powder has superior dispersion characteristics in slurrying, and is capable of partly inhibiting agglomeration of the barium titanate after sintering. It is therefore suitable as materials for dielectric layers of multilayer ceramic capacitors. In particular, the barium titanate has a sintered density of 95% or more of the theoretical density thereof, and the dielectric constant is 4000 or more.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: September 4, 2001
    Assignee: Toho Titanium Co., Ltd.
    Inventors: Hideki Sakai, Matsuhide Horikawa, Wataru Kagohashi
  • Publication number: 20010016552
    Abstract: A high rigidity glass-ceramic substrate for a magnetic information storage medium has a ratio of Young's modulus to specific gravity within a range from 37 to 63 and comprises Al2O3 within a range from 10% to less than 20%. A predominant crystal phase of the glass-ceramic substrate consists of one or more crystals selected from the group consisting of &bgr;-quartz, &bgr;-quartz solid solution, enstatite, enstatite solid solution, forsterite and forsterite solid solution.
    Type: Application
    Filed: November 30, 1998
    Publication date: August 23, 2001
    Inventors: NAOYUKI GOTO, KOUSUKE NAKAJIMA, JUNKO ISHIOKA
  • Patent number: 6268054
    Abstract: Barium titanate-based particles having a coating comprising an oxide, hydrous oxide, hydroxide or organic acid salt of a metal other than barium or titanium, wherein at least 90 percent of said particles have a particle size less than 0.9 micrometer when said particles are dispersed by high shear mixing, useful in the fabrication of thin, fine-grained dielectric layers for multilayer ceramic capacitors with high breakdown voltage.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: July 31, 2001
    Assignee: Cabot Corporation
    Inventors: Stephen A. Costantino, Robert A. Hard, Sridhar Venigalla
  • Patent number: 6266230
    Abstract: The present invention provides a multilayer ceramic capacitor in which electrode metal layers and dielectric ceramic layers are laminated alternately and its dielectric constant peak is present at a temperature below −50° C. The multilayer ceramic capacitor is at least one selected from a multilayer ceramic capacitor to be incorporated into an electric circuit in which an electric field of at least 200 V/mm is applied to dielectric layers as a DC bias electric field and an alternating current at a frequency of at least 20 kHz is superimposed and a multilayer ceramic capacitor to be incorporated into an electric circuit in which an electric field of at least 200 V/mm is applied to dielectric layers as an AC electric field. As the dielectric ceramic, a ceramic containing lead atoms whose amount is indicated by being measured in the form of PbO, which is at least 30 mol %, particularly a compound with a perovskite structure represented by ABO3 is used.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: July 24, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Junichi Kato, Takuya Ishii, Koji Yoshida, Tsutomu Nishimura, Yoshimasa Yabu
  • Publication number: 20010008867
    Abstract: A ceramic for the PTC thermistor having a resistivity at room temperature of 5 &OHgr;·cm or less, static withstanding voltage of 60 V/mm or more and temperature resistance coefficient of 9.0%/° C., having small dispersion of the resistance, is composed of principal components of about 30 to 97 mol % of BaTiO3, about 1 to 50 mol % of PbTiO3, about 1 to 30 mol % of SrTiO3 and about 1 to 25 mol % of CaTiO3 (the total content of them being 100 mol %), as well as about 0.1 to 0.3 mole of Sm, about 0.01 to 0.03 mole of Mn and 0 to about 2.0 mole of Si relative to 100 moles of the principal components, the composite material being preferably heat-treated in an oxidative atmosphere after being fired in a reducing or neutral atmosphere for obtaining the ceramic.
    Type: Application
    Filed: July 23, 1999
    Publication date: July 19, 2001
    Inventors: YASUHIRO NABIKA, TETSUKAZU OKAMOTO, TOSHIHARU HIROTA, NORIYUKI YAMAMOTO
  • Publication number: 20010008866
    Abstract: The present invention provides barium titanate semiconductive ceramic having low specific resistance at room temperature and high withstand voltage, which fully satisfies the demand for enhancing withstand voltage. The average ceramic grain size of the barium titanate semiconductive ceramic is controlled to about 0.9 &mgr;m or less. By this control, the ceramic possesses low specific resistance at room temperature and high withstand voltage fully satisfying a recent demand for enhancing withstand voltage and may suitably used for applications such as controlling temperature and limiting current, or in exothermic devices for constant temperature. Accordingly, the barium titanate semiconductive ceramic enables an apparatus using the same to have enhanced performance and reduced size.
    Type: Application
    Filed: September 18, 1998
    Publication date: July 19, 2001
    Inventors: MITSUTOSHI KAWAMOTO, HIDEAKI NIIMI, RYOUICHI URAHARA, YUKIO SAKABE
  • Patent number: 6258450
    Abstract: The dielectric ceramic composition is composed of a sintered body of ceramic particles containing Ba2Ti5O11 as a major component. The ceramic particles may contain Ag in the form of solid solution at the rate of 0.2% to 3.0% by mole. the ceramic particles may further contain Ba2TiSi2O8 so the BaTi5O11/Ba2TiSi2O8 ratio is 1.5 to 9 BaTi5O11 to 1 Ba2TiSi2O8. The dielectric ceramic composition can be sintered at a low enough temperature to enable a highly conductive metal such as Ag, Cu or the like to be burned and sintered integrally.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: July 10, 2001
    Assignee: Taiyo Yuden Co., Ltd.
    Inventors: Nobuhiro Sasaki, Yoshinao Takahashi, Katsuyuki Horie
  • Patent number: 6254991
    Abstract: The process for preparing ceramic powder having a core-shell structure by dissolving a crystalline ceramic powder In water so as to leave a core portion of the ceramic powder while heating; depositing a component of the ceramic powder dissolved in the water on and around surfaces of the core portion thereof as a deposited material from the water by gradually cooling the ceramic powder and the water obtained in the step of dissolving; and firing a mixture of the ceramic powder obtained in the step of depositing with an additive at a high temperature to subject the deposited material and the additive to solid phase reaction to form a shell portion on and around the core portion of the ceramic powder. The process can produce the ceramic powder having a core-shell structure from a crystalline ceramic powder, thereby achieving high electrical and mechanical features when formed into ceramic electronic parts.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: July 3, 2001
    Assignee: Taiyo Yuden Co., Ltd.
    Inventors: Yasuhisa Kono, Kenji Saito, Yoichi Mizuno, Hirokazu Chazono
  • Patent number: 6231658
    Abstract: A source material for chemical vapor deposition of a lead zirconate titanate ferroelectric thin film, the source material including a solution of organometallic compounds containing lead, zirconium, and titanium dissolved in solvent including tetrahydrofuran.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: May 15, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Fusaoki Uchikawa, Shigeru Matsuno
  • Patent number: 6225250
    Abstract: The present invention provides a dielectric ceramic composition whose electrostatic capacity has an excellently low temperature dependence; which can be fired in a reducing atmosphere; and which is advantageously used in a laminated ceramic capacitor having an internal electrode formed of a base metal such as nickel or nickel alloy. The dielectric ceramic composition is represented by the following formula: {Ba1−xCaxO}mTiO2+&agr;MgO+&bgr;MnO, wherein 0.001≦&agr;≦0.05; 0.001≦&bgr;≦0.025; 1.000<m≦1.035; and 0.02≦x≦0.15.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: May 1, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Wada, Jun Ikeda, Takashi Hiramatsu, Yukio Hamaji
  • Patent number: 6221800
    Abstract: A method of producing a PTC semiconducting ceramic which entails preparing the calcine of a main composition of barium titanate-based semiconductor containing substantially no Si and having BaTiO3 as a main component thereof, preparing additive compositions, Ba2TiSi2O8 and BanTimOn+2m (1≦n≦4,2≦m≦13, n<m), respectively, compounding the calcine of the main composition and the additive compositions and mixing them, and then subjecting them to formal firing. The obtained product exhibits excellent electrical characteristics, which are not influenced by fluctuations in conditions of production.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: April 24, 2001
    Assignee: TDK Corporation
    Inventors: Chihiro Takahashi, Shigeki Sato
  • Patent number: 6214756
    Abstract: A uniform suspension of ceramic powder and method for making the same. The suspension is prepared by mixing finely divided ceramic powder in an aqueous carrier fluid, combining with a dispersing agent, and alternatively, an organic binder when forming a slip. The ceramic powder has an average particle size of about 0.5 micron or less and is present in the suspension in a loading of up to 30% by volume of the total solids in suspension. A passivating agent is present in the carrier fluid in an amount of 0.5 to 5% by weight of the ceramic powder present for suspension and slip respectively. After the addition of a dispersant, the suspension has a Bingham yield point of less than 230 dynes/cm2 and an apparent viscosity of less than 3000 cps. A green layer produced from the slip exhibits a pore size of less than 0.5 micron.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: April 10, 2001
    Assignee: Cabot Corporation
    Inventors: James H. Adair, Stephen A. Costantino
  • Patent number: 6210545
    Abstract: An inventive method for forming a thin film comprises the steps of preparing a sputter-target of a material which is fully oxidized and crystallized to a perovskite structure, sputter-depositing a thin film on top of a sample with the target in an inert gas atmosphere, and annealing the thin film in non-oxygen ambient. With the use of such a target, it is possible to reduce the negative ion effect during the sputter deposition and to eliminate the presence of oxygen during the annealing process.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: April 3, 2001
    Assignee: International Business Machines Corporation
    Inventors: Mukta Farooq, Robert A. Rita, Stephen M. Rossnagel
  • Patent number: 6205015
    Abstract: A dielectric ceramic which exhibits an excellent electrostatic capacity-temperature characteristic; which allows use of a base metal such as nickel; which can be fired in a reducing atmosphere; and which is suitable for constituting a dielectric ceramic layer of a laminated ceramic electronic element such as a laminated ceramic capacitor; is obtained by firing barium titanate powder in which the c-axis/a-axis ratio in the perovskite structure is in the range of about 1.003 to 1.010 and the amount of OH groups in the crystal lattice is about 1 wt. % or less. The barium titanate powder a starting material preferably has a maximum particle size of about 0.5 &mgr;m or less and an average particle size of about 0.1-0.3 &mgr;m, and individual particles of the barium titanate powder comprise a low-crystallinity portion 21 and a high-crystallinity portion 23, with the diameter of the low-crystallinity portion being less than about 0.65 times the particle size of the powder.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: March 20, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Wada, Jun Ikeda, Takashi Hiramatsu, Yukio Hamaji
  • Patent number: 6191934
    Abstract: High dielectric constant capacitors are made from a dielectric ink of lead-magnesium-niobate and lead oxide powders. Dielectric inks are made by mixing the dielectric powders with a suitable organic vehicle which can be used to coat one or more glass-based green tapes. Buried capacitors are made by coating an overlying and an underlying green tape with a conductor such as silver. Capacitors can also be made by adjusting the organic vehicle and forming a green tape from the dielectric powders. These dielectric green tapes each can be coated with a conductive layer and stacked, the conductive layers connected in parallel. The resultant multilayer capacitors have a very high dielectric constant, while eliminating the need for very large area capacitors, as compared to single layer capacitors.
    Type: Grant
    Filed: December 14, 1998
    Date of Patent: February 20, 2001
    Assignees: Sarnoff Corporation & Co., Ltd., Daewoo Electronics Co., Ltd.
    Inventors: Michael James Liberatore, Attiganal Narayanaswamy Sreeram, Ashok Narayan Prabhu, In-Tae Kim, Je-Do Mun, Sung-Dae Park, Yun-Hwi Park, Joo-Dong Yu, Ellen S. Tormey
  • Patent number: 6185087
    Abstract: Multilayer ceramic chip capacitors which satisfy X7R requirements and which are compatible with reducing atmosphere sintering conditions so that non-noble metals such as nickel, copper, and alloys thereof may be used for internal and external electrodes are made in accordance with the invention. The capacitors exhibit desirable dielectric properties (high capacitance, low dissipation factor, high insulation resistance), excellent performance on highly accelerated life testing, and very good resistance to dielectric breakdown. The dielectric layers preferably contain BaTiO3 as the major component and CaTiO3, BaO, CaO, SrO, Si02, MnO2, Y2O3, and CoO as minor components in such proportions so that there are present 0.1 to 4 mol % CaTiO3, 0.1 to 2 mol % BaO, 0 to 1 mol % CaO, 0 to 1 mol % SrO, 0.1 to 5 mol % SiO2, 0.01 to 2 mol % MnO2, 0.1 to 3 mol % Y2O3, and 0.01 to 1 mol % CoO. The preferred form of the invention may be sintered in the temperature range 1,250 to 1,400° C.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: February 6, 2001
    Assignees: Kemet Electronics Corp., Ferro Electronic Materials Inc.
    Inventors: Hyun D. Park, Joseph D. Nance, Mike S. H. Chu, Yuval Avniel
  • Patent number: 6180548
    Abstract: An environment-purifying material is obtained by immersing a carrier with a titanium oxide film coated on its surface or a substrate comprising titanium oxide particles, in a pseudo-body fluid containing an excessive amount of calcium phosphate, and then coating the surface of the substrate with a porous calcium phosphate film that easily adsorbs toxic substances and that is inactive as a photocatalyst.
    Type: Grant
    Filed: August 10, 1998
    Date of Patent: January 30, 2001
    Assignees: Agency of Industrial Science and Technology, JME Co., Ltd.
    Inventors: Hiroshi Taoda, Toru Nonami, Fujio Aramaki, Shoshichi Aramaki
  • Patent number: 6169049
    Abstract: Hydrothermal BaTiO3 crystallites were coated with Bismuth solutions prepared from Bismuth metal-organics and anhydrous solvents. The Bismuth metal-organics were Bi 2-ethylhexanoate and Bi-neodecanoate. Bismuth oxide was also used as a comparison to the Bismuth solutions. BaTiO3 ceramics with either 3.0 wt % equivalent Bismuth oxide or 5.0 wt % equivalent Bismuth oxide were made by sintering the compacts between 700° C. and 1000° C. BaTiO3 ceramics that were coated by Bi-neodecanoate densified >90% theoretical as low as 800° C. for 3.0 wt % equivalent Bi2O3. Average grain sizes of 0.2-0.4 &mgr;m were observed for Bi-coated BaTiO3 ceramics, for sintering temperatures below 950° C. Dielectric K versus temperature measurements of Bismuth-coated BaTiO3 ceramics, sintered in the lower temperature ranges, showed consistently superior dielectric characteristics.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: January 2, 2001
    Inventors: John P. Witham, Clive A. Randall, Umesh Kumar, Ulagaraj Selvaraj, Sea-Fue Wang, Joseph P. Dougherty
  • Patent number: 6162752
    Abstract: The present invention provides barium titanate powder having a withstanding voltage of 800 V/mm or more and a specific resistance at room temperature of 100 .OMEGA..multidot.cm or less, the specific resistance at room temperature undergoing substantially no time-course change. Barium titanate of the powder of the present invention assumes a cubic crystal system. The powder has a particle size of about 0.1 .mu.m or less; the ratio represented by BaCO.sub.3 /BaO as obtained through XPS is about 0.42 or less; the lattice constant is about 0.4020 nm or more; and the ratio represented by Ba/Ti is about 0.988-0.995.
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: December 19, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Mitsutoshi Kawamoto, Hideaki Niimi
  • Patent number: 6153931
    Abstract: The present invention provides a barium titanate-based semiconducting ceramic which exhibits excellent PTC characteristic and which can be fired at a temperature lower than 1000.degree. C. The present invention also provides an electronic element fabricated from the ceramic. The semiconducting ceramic contains, in a semiconducting sintered barium titanate; boron oxide; an oxide of at least one of barium, strontium, calcium, lead, yttrium and a rare earth element; and an optional oxide of at least one of titanium, tin, zirconium, niobium, tungsten and antimony in which the atomic boron is0.005.ltoreq.B/.beta..ltoreq.0.50 and1.0.ltoreq.B/(.alpha.-.beta.).ltoreq.4.0wherein .alpha. represents the total number of atoms of barium, strontium, calcium, lead, yttrium and rare earth element contained in the semiconducting ceramic, and .beta. represents the total number of atoms of titanium, tin, zirconium, niobium, tungsten and antimony contained in the semiconducting ceramic.
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: November 28, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hideaki Niimi, Mitsutoshi Kawamoto, Akinori Nakayama, Satoshi Ueno, Ryouichi Urahara