Abstract: Disclosed herein is a small particle oxide powder for dielectrics. The oxide powder has a perovskite structure, an average particle diameter [D50(?m)] of 0.3 ?m or less, a particle size distribution of the average particle diameter within 3%, a particle size distribution satisfying a condition D99/D50<2.5, a content of OH? groups of 0.2 wt % and a C/A axial ratio of 1.006 or more. A method of manufacturing the oxide powder comprises the steps of mixing TiO2 particles and a compound solved with at least one element represented by A of the perovskite structure of ABO3; drying and pulverizing the mixture of TiO2 and the compound; calcining the pulverized mixture; adding the oxide containing the elements of the site A to the coated TiO2 particles and wet-mixing, drying and pulverizing; primarily calcining and pulverizing the pulverized powder under vacuum; and secondarily calcining and pulverizing the powder.

Abstract: The present invention provides a thin film type multi-layered ceramic capacitor including a stacked body composed of a plurality of capacitor layers. Each of the capacitor layers comprises a substrate having an upper surface where a plurality of holes are formed and a flat lower surface, and a thin film capacitor on the upper surface of the substrate. The thin film capacitor includes a lower electrode film, a dielectric film, and an upper electrode film. The lower electrode film, the dielectric film, and the upper electrode film are formed in sequence on the upper surface of the substrate. The lower and the upper electrode films extend to one side and the other side of the substrate and contact first and second external electrodes, respectively.

Abstract: The non reducible dielectric ceramic composition comprising a main component of (Ba1-xCax)m(Ti1-yZry)O3, subcomponents of MgO, Re2O3, MO, MnO and V2O5 where Re is one or more elements selected from the group of Y, Dy and Ho and M is one or two elements selected from the group of Ba and Ca, and a sintering aid of SiO2, wherein when the composition is represented by the formula 100(Ba1-xCax)m(Ti1-yZry)O3+bMgO+cRe2O3+dMO+eMnO+fV2O5+gSiO2, the ratio of the components satisfies the conditions of 0.005?x?0.15, 0.995?m?1.03, 0.0005?y?0.005, 0.1?b?3.0, 0.1?c?3.0, 0.05?d?2.0, 0.05?e?50.3, 0.0.?f?0.1, and 0.2?g?3.0 based on the molar ratio.

Abstract: Disclosed herein are a multilayer ceramic capacitor, a dielectric composition capable of sintering at a lower temperature and having a small variation in dielectric constant, a multilayer ceramic capacitor using the same, and a method thereof. The dielectric composition includes BaTiO3, MgCO3, Y2O3, Cr2O3, Mn2V2O7, and xBaO-yZrO2-zSiO2 acting as a sintering agent (where 0.1?x?0.3, 0.1?y?0.3 and 0.4?z?0.8, x+y+z=1), wherein when representing the composition with the formula aBaTiO3-bMgCO3-cY2O3-dCr2O3-e(Mn2V2O7)-f(xBaO-yZrO2-zSiO2), the ratio of the components satisfies the conditions of a=100, 0.1?b?3.0, 0.3?c?2.0, 0.05?d?0.2, 0.01?e?1.5, 0.5?f?3.0 based on the molar ratio. When manufacturing a multilayer ceramic capacitor of a higher capacitance, which is formed to have the thin layer structure of 4 ?m or less, short circuits between internal electrodes and the deterioration in capacitance due to massing of the electrodes into ball at the ends may be remarkably reduced.

Abstract: A low temperature sinterable dielectric ceramic composition and a multilayer ceramic chip capacitor. The dielectric ceramic composition is expressed by the general formula: aBaTiO3-bMgCO3-cY2O3-dCr2O3-eV2O5-f(xZrO2-y(K,Li)2O-zSiO2) (x+y+z=1; 0.05?x?0.18, 0.01?y?0.08, and 0.7.4?z?0.93); in which a, b, c, d, e and f are molar ratios; a=100, 1.0?b?2.0, 0.2?c?2.0, 0.02?d?0.3, 0.02?e?0.3, and 0.5?f<2. The multilayer ceramic chip capacitor is prepared using the dielectric ceramic composition. The dielectric composition according to the present invention can be sintered at a low temperature without decrease of a dielectric constant, making it possible to make ultra thin-layered dielectrics.

Abstract: A dielectric ceramic composition of high dielectric constant and low dielectric loss, which can be co-fired with Ag electrodes, is provided for use in various parts of electric and electronic appliances. Based on a base composition with a high dielectric constant, the composition comprises glass frit and optionally CuO, as represented by the following formula: a wt. % {x CaO-y1 Sm2O3-y2 Nd2O3-w Li2O-z TiO2}+b wt. % (ZnO—B2O3—SiO2 based or Li2O—B2O3—SiO2 based glass frit)+c wt. % CuO wherein, 13.0 mol %?x?20.0 mol %; 10.0 mol %?y1+y2?17.0 mol %; 6.0 mol %?w?11.0 mol %; 60.0 mol %?z?67.0 mol % with the proviso that x+y1+y2+w+z=100; 85.0 wt. %?a?97.0 wt. %; 3.0 wt. %?b?15.0 wt. %; and c?7.0 wt. %.

Abstract: The present invention relates to a method for preparing barium titanate based powder. More particularly, the present invention provides a method for preparing barium titanate powder comprising the following steps of precipitation of barium titanyl oxalate (BaTiO(C2O4)2.4H2O) with spraying a mixture of an aqueous barium chloride (BaCl2.2H2O) and titanium tetrachloride (TiCl4) to an aqueous solution of oxalic acid, via a nozzle; wet pulverization by using a beads mill after adding an additive such as an amine; dry; pyrolysis; and re-pulverization.

Abstract: Multilayer ceramic chip capacitors which satisfy X5R (−55 to 85° C., &Dgr;C=±15%) requirements and which are compatible with reducing atmosphere sintering conditions so that base metals such as nickel and nickel alloys may be used for internal electrodes are made in accordance with the invention. The multilayer ceramic chip capacitor comprises alternately staked, dielectric ceramic layers and internal electrode layers wherein dielectric ceramic layers comprise per 100 mol of BaTiO3, BaTiO3; MgCO3: 0.2 to 3.0 mol; at least one selected from Y2O3, Ho2O3, Dy2O3 and Yb2O3: 0.05 to 1.5 mol; Cr2O3: 0.1 to 1.5 mol; BaxCa(1−x)SiO3 (provided that 0≦x≦1): 0.2 to 3.0 mol; and Mn2V2O7: 0.01 to 1.5 mol. The multilayer ceramic chip capacitor of the present invention has a high dielectric constant, satisfies X5R characteristics can be sintered at a low temperature of 1,200 to 1,250° C.

Abstract: The present invention relates to a method for preparing high quality barium titanate powder by precipitating barium titanyl oxalate with spraying a mixture of an aqueous barium chloride and titanium tetrachloride (TiCl4) to an aqueous solution of oxalic acid via a nozzle in high speed, which exhibits improved yield with shortened reaction time and optimized stoichiometric mole ratio of barium to titanium, thus suitable materials for multilayer ceramic capacitors, PTC thermistors, resistors, and the like.

Abstract: A low temperature sinterable dielectric ceramic composition and a multilayer ceramic chip capacitor. The dielectric ceramic composition is expressed by the general formula: aBaTiO3-bMgCO3-cY2O3-dCr2O3-eV2O5-f(xZrO2-y(K,Li)2O-zSiO2) (x+y+z=1; 0.05≦x≦0.18, 0.01≦y≦0.08, and 0.7.4≦z≦0.93); in which a, b, c, d, e and f are molar ratios; a=100, 1.0≦b≦2.0, 0.2≦c≦2.0, 0.02≦d≦0.3, 0.02≦e≦0.3, and 0.5≦f<2. The multilayer ceramic chip capacitor is prepared using the dielectric ceramic composition. The dielectric composition according to the present invention can be sintered at a low temperature without decrease of a dielectric constant, making it possible to make ultra thin-layered dielectrics.

Abstract: A dielectric ceramic composition of high dielectric constant and low dielectric loss, which can be co-fired with Ag electrodes, is provided for use in various parts of electric and electronic appliances. The composition is represented by the following chemical formula: a wt. % {x BaO—y1Nd2O3—y2Sm2O3—w Bi2O3—z TiO2}+ b wt. % (ZnO—B2O3—SiO2—PbO based glass frit)+ c wt. % CuO wherein, 10.0 mol %≦x≦20.0 mol %; 7.0 mol %≦y1+y2≦20.0 mol %; 0.5 mol %≦w≦5.0 mol %; 60.0 mol %≦z≦80.0 mol %, with the proviso that x+y1+y2+w+z=100; 80.0 wt. %≦a≦98.0 wt. %; 1.0 wt. %≦b≦10.0 wt. %; 1.0 wt. %≦c≦10.0 wt. %.

Abstract: A dielectric ceramic composition of high dielectric constant and low dielectric loss, which can be co-fired with Ag electrodes, is provided for use in various parts of electric and electronic appliances. The composition is represented by the following chemical formula: a wt. % {xZrO2−yZnO−wNb2O5−zTiO2}+cwt. % glass frit wherein, 5.0 mol %≦x≦45.0 mol %; 1.5 mol %≦y≦19.0 mol %; 1.5 mol %≦w≦19.0 mol %; 40.0 mol %≦z≦59.0 mol % with the proviso that x+y+w+z=100, 75.0≦a≦97.0, and 3.0≦c≦25.0.

Abstract: A dielectric compound for a multilayer ceramic condenser having a low sintering temperature and a high dielectric constant includes a base material of (BaxCa1−x)m(TiyZr1−y)O3 (where 0.7≦x≦1, 0.75≦y≦0.9, 0.998≦m≦1.006), an additive including MnO2 of less than 0.8 weight %, Y2O3 of less than 0.8 weight %, V2O5 of 0˜0.1 weight %, and a sintering aid of zLi2O−2(1−z)SiO2 (0.2≦z≦0.9) of less than 1.0 weight %. The weight % is a ratio relating to a weight of base material of the dielectric compound.

Abstract: Disclosed is a method for preparing barium titanate powder by oxalate synthesis, whereby barium titanate powder or doped barium titanate powder with excellent powder properties can be produced at high efficiency and with economic benefit. An aqueous solution containing barium chloride and titanium chloride or further containing at least one dopant serving as a donor or acceptor is mixed with an aqueous oxalic acid solution to afford barium titanyl oxalate (BTO) or doped-BTO as a precipitate which is then aged, washed, and dried, followed by primary calcination and pulverization and secondary calcination and pulverization.

Abstract: The present invention provides a piezoelectric ceramic composition having the formula: {[Pb(1−1.5x)±(0˜0.2)Lax][Ti(1−y−z)MnyCuz]O3} which meets the requirements: 0.02<x<0.14, 0.01≦y<0.04, and 0.002≦z≦0.008. The piezoelectric ceramic composition of the present invention can be stably sintered under normal atmosphere. That is, there is no need for an oxygen partial pressure to be 80% or more. Furthermore, the composition exhibits excellent piezoelectric property and thermal stability. Accordingly, the piezoelectric ceramic composition of the present invention has excellent piezoelectric property at a thickness longitudinal third harmonic frequency capable of producing a high frequency of 15 MHz or more, and can be used as a material of a piezoelectric ceramic device with a small electrode area.

Abstract: Multilayer ceramic chip capacitors which satisfy X5R (−55 to 85° C., &Dgr;C=±15%) requirements and which are compatible with reducing atmosphere sintering conditions so that base metals such as nickel and nickel alloys may be used for internal electrodes are made in accordance with the invention.

Abstract: A dielectric compound for a multilayer ceramic condenser having a low sintering temperature and a high dielectric constant includes a base material of (BaxCa1−x)m(TiyZr1−y)O3 (where 0.7≦x≦1, 0.75≦y≦0.9, 0.998≦m≦1.006), an additive including MnO2 of less than 0.8 weight %, Y2O3 of less than 0.8 weight %, V2O5 of 0˜0.1 weight %, and a sintering aid of zLi2O−2(1−z)SiO2 (0.2≦z≦0.9) of less than 1.0 weight %. The weight % is a ratio relating to a weight of base material of the dielectric compound.

Abstract: Disclosed is a piezoelectric ceramic composition comprising a PZT piezoelectric composition, a B-site of which is substituted with a certain material, and chromium oxide, and a piezoelectric device using the piezoelectric ceramic composition. The piezoelectric ceramic composition has good heat resistance and frequency stability, and reduces a leakage current. There is provided the piezoelectric ceramic composition comprising a main component expressed by Pb[(Co1/2W1/2)xTi1−x−yZry]O3 (wherein, 0.001≦x≦0.04, and 0.35 ≦y≦0.55), Cr2O3 in an amount of 0.01 to 2 wt %, MnO2 in an amount of 0.1 to 0.5 wt %, and an additive in an amount of 0.01 to 2.0 wt %, based on the total weight of the piezoelectric ceramic composition, in which the additive is selected from the group consisting of CoO, MgO, ZnO, Al2O3, Fe2O3, Sb2O3, SnO2, CeO2, Nb2O5, V2O5 and WO3, and mixtures thereof.

Abstract: Disclosed is a dielectric composition, which is advantageous in light of increased homogeneity and insulation resistance, a method of preparing the same and a multi-layer ceramic capacitor using the same. The dielectric composition consists of a dielectric component represented by (Ba1−x−yCaxAy)m(Ti1−a−b−cZraB′bB″c)O3+m, (wherein, 0.01≦x≦0.10, 0.003≦y≦0.015, 0.16≦a≦0.20, 0.003≦b≦0.015, 0≦c≦0.015, 1.000≦m≦1.010; the component A is selected from among Y oxides, La oxides, Ho oxides, Dy oxides, Er oxides, Hf oxides and combinations thereof; the component B′ is selected from among Mn oxides, Co oxides, Ni oxides and combinations thereof; and the component B″ is selected from among V oxides, Nb oxides, Ta oxides and combinations thereof), and a sintering aid represented by zLi2O-2(1−z)SiO2(0≦Z≦0.9).

Abstract: The method is carried out in the following manner: An aqueous mixture solution containing barium chloride and titanium chloride is added into an aqueous oxalic acid solution, so that barium titanyl oxalate would be precipitated. Then the precipitates are aged, washed and filtered. The filtered barium titanyl oxalate precipitates are crushed, and dried. Then a thermal decomposition is carried out to obtain a agglomerated barium titanate powder, and this is crushed again to obtain the final barium titanate powder. In order to obtain barium titanate based powder such as Ba(Ti1−zZrz)O3, (Ba1−xCax)(Ti1−zZrz)O3, and (Ba1−x−yCaxSry)(Ti1−zZrz)O3, the desired elements (Ca, Sr, Zr and so on) are added to barium titanyl oxalate when crushed before thermal decomposition step. After thermal decomposition and crushing, the barium titanate based powder can be obtained.