And Trivalent Metal Oxide Patents (Class 501/139)
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Patent number: 5256639Abstract: A dielectric ceramic composition represented by the compositional formula: .sub.x BaO-.sub.y TiO.sub.2 -.sub.z Nd.sub.2 O.sub.3 -.sub.t Sm.sub.2 O.sub.3 -.sub.w Bi.sub.2 O.sub.3 so composed as to be in the molar fractions of 0.06.ltoreq.x.ltoreq.0.25, 0.60.ltoreq.y.ltoreq.0.80, 0.05.ltoreq.z.ltoreq.0.18, 0<t.ltoreq.0.07 and 0<w.ltoreq.0.05, provided that x+y+z+t+w=1, and a compositional range of Y<0.68 and Z>0.15 is excluded. As an additive, at least one of Al.sub.2 O.sub.3, ZrO.sub.2, etc. may be added. Part of Ba may be replaced with at least one of Sr, Ca and Mg. The Sm.sub.2 O.sub.3 and Nd.sub.2 O.sub.3 each may have a purity of at least 70 wt. %.Type: GrantFiled: September 21, 1992Date of Patent: October 26, 1993Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takuya Fujimaru, Takehiko Yoneda, Hiromi Tokunaga, Hiromitsu Taki
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Patent number: 5248640Abstract: A non-reducible dielectric ceramic composition comprises of a basic composition expressed by the general formula:{(Ba.sub.1-x-y Sr.sub.x Ca.sub.y)O}.sub.m (Ti.sub.1-o-p Zr.sub.o Nb.sub.p)O.sub.2+p/2wherein 0.05.ltoreq.x 0.30, 0.005.ltoreq.y.ltoreq.0.12, 0.ltoreq.o.ltoreq.0.20, 0.0005.ltoreq.p.ltoreq.0.012, and 1.002.ltoreq.m.ltoreq.1.03, or{(Ba.sub.1-x-y-z Sr.sub.x Ca.sub.y Mg.sub.z)O}.sub.m (Ti.sub.1-o-p Zr.sub.o Nb.sub.p)O.sub.2+p/2wherein 0.05.ltoreq.x.ltoreq.0.35, 0.005.ltoreq.y 0.12, 0.0005 .ltoreq.z.ltoreq.0.05, 0<o.ltoreq.0.20, 0.0005.ltoreq.p.ltoreq.0.02, 1.000.ltoreq.m.ltoreq.1.04. The composition contains an additive (A) composed of one or more oxides selected from the group of MnO.sub.2, Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, CoO and NiO in an amount of 0.02 to 2.0 moles per 100 moles of the basic composition. The composition further contains an additive (B) consisting of SiO.sub.2 and/or ZnO in an amount of 0.1 to 2.Type: GrantFiled: September 25, 1992Date of Patent: September 28, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Harunobu Sano, Yukio Hamaji, Yukio Sakabe
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Patent number: 5244851Abstract: A microwave ceramic composition containing as main components substances expressed by a composition formula of x.BaO - y TiO.sub.2 - z.Nd.sub.2 O.sub.3 (where 0.05<=x<=0.25, 0.60<=y<=0.85, and 0.05<=z<=0.225) when their molar fractions are taken as x, y and z (x+y+z=1) and containing as a subcomponent one type selected from the group consisting of In.sub.2 O.sub.3, Bi.sub.2 O.sub.5, GeO.sub.2 and V.sub.2 O.sub.5.Type: GrantFiled: February 21, 1992Date of Patent: September 14, 1993Assignee: Sanyo Electric Co., Ltd.Inventors: Hisakazu Takahashi, Yoko Baba, Kenichi Ezaki, Yasuhiko Okamoto, Kenichi Shibata, Kazuhiko Kuroki
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Patent number: 5238673Abstract: A composition consisting essentially of 60.0-70.0 mol % TiO.sub.2, 14.3-20.0 mol % Nd.sub.2 O.sub.3, 11.0-16.7 mol % BaO, 1.0-8.0 mol % ZrO.sub.2 and 0.05-0.30 mol % CeO.sub.2. This composition is useful for forming densified ceramic dielectric bodies having a dielectric constant of at least 65 and which meet COG specifications, and multilayer capacitors that contain such dielectric bodies.Type: GrantFiled: May 26, 1992Date of Patent: August 24, 1993Assignee: E. I. Du Pont de Nemours and CompanyInventors: Salvatore A. Bruno, Ian Burn
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Patent number: 5232880Abstract: A nonreducible dielectric ceramic composition of a system, (A.sub.1-x R.sub.x).sub.y BO.sub.3, is prepared by preparing a slurry containing at least one compound selected from the group consisting of carbonates and hydroxides of Ba, Sr, Ca and Mg, at least one compound selected from the group consisting of carbonates and hydroxides of rare earth elements R, and at least one compound selected from the group consisting of oxides, carbonates and hydroxides of Ti, Zr and Sn; filtering the resulting slurry; washing the filter cake with water and calcining the resulting washed cake.Type: GrantFiled: January 9, 1992Date of Patent: August 3, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Nobuyuki Wada, Yoshiaki Kohno, Shozo Kojima, Syunsuke Nakaya
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Patent number: 5223462Abstract: A dielectric ceramic composition of matter characterized in that the composition of matter contains 0.003 to 0.3% by weight manganese in addition to the main composition of matter represented by the composition formula xBaO.multidot.yNd.sub.2 O.sub.3 .multidot.zTiO.sub.2 .multidot.wBi.sub.2 O.sub.3 wherein 0.110.ltoreq.x.ltoreq.0.170, 0.120.ltoreq.y.ltoreq.0.185, 0.630.ltoreq.z.ltoreq. 0.710, 0.020.ltoreq.w.ltoreq.0.090, and x+y+z+w=1. This composition of matter is high in dielectric constant, low in the temperature dependency of resonance frequency in a resonator, and high in Q-value.Type: GrantFiled: January 21, 1992Date of Patent: June 29, 1993Assignee: Kyocera CorporationInventor: Takashi Okawa
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Patent number: 5219812Abstract: A dielectric ceramic composition containing 0.3 to 5.0 parts by weight of an additive composed of at least one of SiO.sub.2, Li.sub.2 O and B.sub.2 O.sub.3 per 100 parts by weight of a main component expressed by the following composition formula:(1-x-y-z-t)BaTiO.sub.3 +xCaZrO.sub.3 +yMgO+zMnO+tRe.sub.2 O.sub.3,wherex.ltoreq.0.060.005.ltoreq.y.ltoreq.0.080.005.ltoreq.z.ltoreq.0.020.005.ltoreq.t.ltoreq.0.02.In the composition formula, Re indicates at least one of Y, Gd, Dy, Ho, Er and Yb.Type: GrantFiled: February 18, 1992Date of Patent: June 15, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Tetsuya Doi, Takuya Miyagawa, Yasuyuki Naito, Tadashi Morimoto
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Patent number: 5219811Abstract: To produce a modified barium titanate ceramic which is semiconductive and sufficiently high in breakdown voltage and has a low specific resistance at room temperature and a high positive temperature coefficient (PTC) of resistance, the invention provides a powder composition comprising (A) a basic mixture consisting of 45-85 mol % of BaTiO.sub.3 powder, 1-20 mol % of SrTiO.sub.3 powder, 5-20 mol % of CaTiO.sub.3 powder and 1-20 mol % of PbTiO.sub.3 powder, (B) a source of a dopant element such as Nb, Sb, Y, La or Ce to render the ceramic semiconductive, (C) a source of Mn such as MnC.sub.2 O.sub.4 and/or a source of Cu such as CuO added such that the total amount of Mn and Cu is not more than 0.06 mol % on the basis of the quantity of the mixture (A) with proviso that the amount of Mn is not more than 0.025 mol % and (D) SiO.sub.2 amounting to 0.1-2.0 mol % on the basis of the quantity of the mixture (A). The BaTiO.sub.3 powder and the SrTiO.sub.3 powder are produced by calcining BaTiO(C.sub.2 O.sub.4).sub.Type: GrantFiled: February 27, 1992Date of Patent: June 15, 1993Assignee: Central Glass Company, LimitedInventors: Takamitsu Enomoto, Midori Kawahara, Noboru Murata, Hiroshi Ueda, Naoki Okada
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Patent number: 5202814Abstract: A nonreducing dielectric ceramic composition. A main component includes oxides of Ba, Ca, Mg, Sr, Ce, Ti and Zr, and in the general formula represented by (Ba.sub.l-m-n-o Sr.sub.l Ca.sub.m Mg.sub.n Ce.sub.o).sub.q (Ti.sub.1-p Zr.sub.p)O.sub.3. In this formula l, m, n, o, p and q satisfy the relationships, 0.05.ltoreq.l.ltoreq.0.30, 0.005.ltoreq.m.ltoreq.0.22, 0.0005.ltoreq.n.ltoreq.0.05, 0.0005.ltoreq.o.ltoreq.0.02, 0.ltoreq.p.ltoreq.0.20, 1.002.ltoreq.q.ltoreq.l.03. The composition includes between 0.02 to 2.0 mole % of one or more of the following oxides MnO.sub.2, Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3 and CoO.Type: GrantFiled: June 24, 1992Date of Patent: April 13, 1993Assignee: Murata Manufacturing Co., Ltd.Inventors: Yoshiaki Kohno, Nobuyuki Wada
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Patent number: 5185304Abstract: A dielectric ceramic composition is disclosed which consists principally of barium oxide, titanium oxide, neodymium oxide, samarium oxide and bismuth oxide, which are represented by the following formula xBaO--yTiO.sub.2 --z[(1-a-b)Nd.sub.2 O.sub.3 --aSm.sub.2 O.sub.3 --bBi.sub.2 O.sub.3 ], where 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.24, x+y+z=1, 0<a.ltoreq.0.25 and 0<b.ltoreq.0.30. Also disclosed is a dielectric ceramic composition which consists principally of: barium oxide, titanium oxide, neodymium oxide, samarium oxide and bismuth oxide as major components which are represented by the following formula xBaO--yTiO.sub.2 --z[1-a-b)Nd.sub.2 O.sub.3 -aSm.sub.2 O.sub.3 --bBi.sub.2 O.sub.3 ], where 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.25, x+y+z=1, 0<a.ltoreq.0.30 and 0<b.ltoreq.0.35; and not more than 2.0 parts by weight of alumina per 100 parts by weight of a total of the major components.Type: GrantFiled: August 15, 1991Date of Patent: February 9, 1993Assignee: NGK Insulators, Ltd.Inventors: Takami Hirai, Shinsuke Yano, Masahiro Abe
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Patent number: 5182240Abstract: A dielectric ceramic composition is disclosed which consists principally of: barium oxide, titanium oxide, neodymium oxide and samarium oxide as major components which are represented by the following formula xBaO - yTiO.sub.2 - z[(1 - a)Nd.sub.2 O.sub.3 - aSm.sub.2 O.sub.3 ], where 0.10.ltoreq.x.ltoreq.0.20, 0.60.ltoreq.y.ltoreq.0.75, 0.10.ltoreq.z.ltoreq.0.25, x+y+z=1, and 0<a.ltoreq.0.50; and not larger than 2.5 parts by weight of alumina per 100 parts by weight of a total amount of the major components.Type: GrantFiled: August 15, 1991Date of Patent: January 26, 1993Assignee: NGK Insulators, Ltd.Inventors: Takami Hirai, Shinsuke Yano
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Patent number: 5155072Abstract: A composition comprising finely divided particles of modified barium titanate; and an admixture of calcium, titanium and manganese; the modified barium titanate particles containing Zr, Zn and Nb homogeneously distributed on an atomic scale throughout the particles according to the formula:BaTi.sub.1-(x+3y/2) (Zr.sub.x Zn.sub.y/2 Nb.sub.y) O.sub.3wherein x=0.01-0.20 and y=0.005-0.075. This composition forms a dielectric layer having a Curie Temperature below 25.degree. C., a dielectric constant of at least 10,000 and grain size of 5 microns or less and is useful in multilayer electrical devices such as circuits and capacitors.Type: GrantFiled: June 29, 1990Date of Patent: October 13, 1992Assignee: E. I. Du Pont de Nemours and CompanyInventors: Salvatore A. Bruno, Ian Burn
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Patent number: 5130281Abstract: The dielectric ceramic composite according to the invention contains at least one kind of lanthanum oxide, cerium oxide, neodymium oxide, praseodymium oxide and samarium oxide at an amount of 2.5-5.0 mol % and zirconium oxide, tin oxide and titanium oxide at an amount of 0.5-8.5 mol% in a formula (Zr.sub.1-a-b Sn.sub.a Ti.sub.b) O.sub.3 (where a>0, b.gtoreq.0, 0<a+b.ltoreq.1.0) to barium titanate of 100 mol % containing alkali metal oxide less than 0.03% by weight as an impurity. Barium zirconate and barium stannate at an amount of 0.5-5.0 mol % in a formula Ba (Zr.sub.1-a Sn.sub.a) O.sub.3 (where 0<a.ltoreq.1.0) and titanium oxide at an amount of 1.5-6.0 mol % may be added instead of zirconium oxide, tin oxide, titanium oxide.Type: GrantFiled: July 9, 1991Date of Patent: July 14, 1992Assignee: Murata Manufacturing Co., Ltd.Inventors: Harunobu Sano, Nobuyuki Wada, Yoshiaki Kohno, Yukio Sakabe
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Patent number: 5128290Abstract: The present invention provides microwave ceramic dielectric materials having large relative dielectric constant, very large Q, and stable and small temperature coefficient.The ceramic dielectric materials of the present invention are expressed by the general formula:[{BaO}.sub.x {TiO.sub.2 }.sub.y {(Sm.sub.2 O.sub.3).sub.1-m-n (SrO.cndot.CeO.sub.2).sub.m (CaO.cndot.CeO.sub.2).sub.n }.sub.z ].sub.1-A [SrTiO.sub.3 ].sub.Awherein, 0.1.ltoreq.x.ltoreq.0.25, 0.6.ltoreq.y.ltoreq.0.85, 0.05.ltoreq.z.ltoreq.0.3, 0.ltoreq.m.ltoreq.0.80, 0.ltoreq.n<0.8, x+y+z=1, m+n.ltoreq.0.8, x+y+z=1, 0<A.ltoreq.0.40; x,y,z are expressed by mol fraction.Type: GrantFiled: June 26, 1991Date of Patent: July 7, 1992Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Akira Yamada, Toshihisa Honda, Hisao Watarai, Kiyoshi Saitou, Yoshikazu Utsumi
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Patent number: 5128289Abstract: A barium titanate based dielectric ceramic composition having a temperature coefficient range of about +/-15% form its value at 25.degree. C. over a temperature range of -55.degree. C. to 125.degree. C., and a dielectric constant in excess of 5000, is prepared from a ternary system comprising barium titanate, nickel niobate and manganese niobate in the molar ratios of approximately 97.23 mole % of BaTiO.sub.3, 2.35 mole % of NiO.sub.(1-x).NbO.sub.2.5(x), and 0.42 mole % of MnO.sub.1-y).NbO.sub.2.5(y), where x may equal approximately 0.73 and y approximately 0.53. Tantalum is also used in place of the niobium.Type: GrantFiled: December 7, 1990Date of Patent: July 7, 1992Assignee: Ferro CorporationInventor: James M. Wilson
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Patent number: 5116790Abstract: A composition consisting essentially of 60.0-70.0 mol % TiO.sub.2, 14.3-20.0 mol % Nd.sub.2 O.sub.3, 11.0-16.7 mol % BaO, 1.0-8.0 mol % ZrO.sub.2 and 0.05-0.30 mol % CeO.sub.2. This composition is useful for forming densified ceramic dielectric bodies having a dielectric constant of at least 65 and which meet COG specifications, and multilayer capacitors that contain such dielectric bodies.Type: GrantFiled: November 16, 1990Date of Patent: May 26, 1992Assignee: E. I. Du Pont de Nemours and CompanyInventors: Salvatore A. Bruno, Ian Burn
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Patent number: 5103369Abstract: A monolithic capacitor having a dielectric ceramic body cosintered with at least two base metal electrodes. The ceramic body is composed of a major ingredient expressed by the formula,(1--.alpha.) {(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+.alpha.CaZrO.sub.3where M is either or both of magnesium and zinc, L is either or both of calcium and magnesium, R is a rare earth element or elements, and .alpha., k, x, z and y are numerals in specified ranges. To this major ingredient is added a minor proportion of a first additive ingredient and a second additive ingredient. The first additive ingredient is at least either of chromium oxide and aluminum oxide. The second additive ingredient is a mixture of boric oxide or lithium oxide, silicon dioxide and at least one metal oxide selected from among barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide.Type: GrantFiled: November 29, 1990Date of Patent: April 7, 1992Assignee: Taiyo Yuden Co., Ltd.Inventors: Hiroshi Saito, Mutsumi Honda, Hiroshi Kishi, Hisamitsu Shizuno, Hirokazu Chazono
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Patent number: 5096642Abstract: A process for producing a high density ceramic of perovskite represented by the formula:ABO.sub.Type: GrantFiled: December 15, 1987Date of Patent: March 17, 1992Assignee: National Institute for Research In Inorganic MaterialsInventor: Shin-ichi Shirasaki
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Patent number: 5094987Abstract: Dielectric ceramic composition consisting essentially of substance selected from those represented by the following formula:Pb.sub.1-x+a Me.sub.x {(Zn.sub.1/3 Nb.sub.2/3)1.sub.-y-z Ti.sub.y (Cu.sub.b M.sub.1-b).sub.2 }O.sub.3+awherein Me is at least one element selected from Sr and Ba; M is at least one element selected from Nb, Ta and W; x and y are within the scope shown in FIGS. 1, 3 or 2; and O.ltoreq.a.ltoreq.0.1, 0.02.ltoreq.b.ltoreq.1.0, 0.002.ltoreq.bz.ltoreq.0.04.Multi-layer capacitors having dielectric layers made of the dielectric ceramic composition exhibit a good temperature coefficient of capacitance.Type: GrantFiled: August 17, 1990Date of Patent: March 10, 1992Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiroshi Kagata, Junichi Kato, Youichiro Yokotani, Koichi Kugimiya
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Patent number: 5091348Abstract: The invention concerns sol-gel techniques for making PZT-type ceramics having a perovskite-type structure and ferrite ceramics having a spinel-type structure. Colloidal hydrated oxide sols are mixed with metal salt solutions in the required concentration and the mixed sols dehydrated to form homogeneous gels which are fired at 250.degree. C.-650.degree. C., pressed and sintered at 900.degree.-1300.degree. C. The resulting ceramics include PZT4, PZT5 and lithium ferrites. These have excellent homogeneity, small grain size, high density and improved electrical properties, particularly low dielectric loss, compared with known ceramics of similar composition.Type: GrantFiled: April 17, 1989Date of Patent: February 25, 1992Assignee: Alcan International LimitedInventors: James L. Woodhead, Paul Groves
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Patent number: 5089933Abstract: A monolithic capacitor having a dielectric ceramic body cosintered with at least two base metal electrodes. The ceramic body is composed of a major ingredient expressed by the formula(1-.alpha.){(Ba.sub.k-x M.sub.x)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+.alpha.CaZrO.sub.3where M is either or both of calcium and strontium, R is a rare earth element or elements, and .alpha., k, x and y are numerals in specified ranges. To this major ingredient is added a minor proportion of a first additive ingredient and a second additive ingredient. The first additive ingredient is at least either of chromium oxide and aluminum oxide. The second additive ingredient is a mixture of boric oxide or lithium oxide, silicon dioxide and at least one metal oxide selected from among barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide.Type: GrantFiled: November 29, 1990Date of Patent: February 18, 1992Assignee: Taiyo Yuden Co., Ltd.Inventors: Hiroshi Saito, Mutsumi Honda, Hiroshi Kishi, Hisamitsu Shizuno, Hirokazu Chazono
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Patent number: 5084426Abstract: A semiconductive ceramic composition capable of permitting its resistance-temperature characteristics and resistance to be controlled as desired and a firing temperature of the composition to be lowered to a degree sufficient to facilitate the mass-production at a low cost. The composition contains a main component consisting of SrO, PbO and TiO.sub.2 and is subjected to firing in an oxidizing atmosphere. The composition may contain at least one of SiO.sub.2 and M as a minor component. A variation in amount of the main and minor components permits characteristics and properties of the composition to be varied as desired.Type: GrantFiled: July 13, 1989Date of Patent: January 28, 1992Assignee: TDK CorporationInventors: Shoichi Iwaya, Hitoshi Masumura, Haruo Taguchi, Munemitsu Hamada, Tomohiro Sogabe, Shigeya Takahashi, Hiroyuki Satoh
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Patent number: 5077247Abstract: A dielectric ceramic for microwave applications is comprised of:X BaO.Y TiO.sub.2.Z {(Sm.sub.2 O.sub.3).sub.1-W1-W2 (La.sub.2 O.sub.3).sub.W1 (Nd.sub.2 O.sub.3).sub.W2 }where X, Y, Z lie in the ranges: 11.0.ltoreq.X.ltoreq.22.0; 60.0.ltoreq.Y.ltoreq.75.0; and 6.0.ltoreq.Z.ltoreq.28.0 (X+Y+Z=100) expressed in mole %, and 0<W.sub.1 .ltoreq.0.35; 0<W.sub.2 <1; and 0<(1-W.sub.1 -W.sub.2)<1; where W.sub.1, W.sub.2 and (1-W.sub.1 -W.sub.2) are mole ratios. MnO.sub.2 or Al.sub.2 O.sub.3 may also be added.Alternatively, a dielectric ceramic may comprise:X BaO.Y TiO.sub.2.Z {(Sm.sub.2 O.sub.3).sub.1-W1-W2 (La.sub.2 O.sub.3).sub.W1 (Nd.sub.2 O.sub.3).sub.W2 }.V Bi.sub.2 O.sub.3where X, Y, Z and V lie in the ranges: 11.5.ltoreq.X.ltoreq.21.0; 60.0.ltoreq.Y.ltoreq.76.0; 6.5.ltoreq.Z.ltoreq.26.0; and 0.1.ltoreq.V.ltoreq.5.0 (X+Y+Z+V=100), expressed in mole %, and 0<W.sub.1 <1; 0<W.sub.2 <1; 0.ltoreq.(1-W.sub.1 -W.sub.2)<1, where W.sub.1, W.sub.2 and (1-W.sub.1 -W.sub.2) are mole ratios. MnO.Type: GrantFiled: August 6, 1990Date of Patent: December 31, 1991Assignee: Oki Electric Industry Co., Ltd.Inventors: Hosaku Sato, Ayusawa Kazutoshi, Toru Arai
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Patent number: 5043305Abstract: The ceramic sinter is composed of a metal oxide such as ZrO.sub.2 and 10-90 vol. % of metal fluoride which is selected from the group having not less than 2.5 electronegativity difference between fluoride and the metal element.The ceramic sinter has a thermal expansion coefficient of 15-20.times.10.sup.-6 /.degree.C. and is suitable for bonding with general use metals such as stainless steel to form a composite body of the ceramic sinter and the metal without causing a substantial thermal stress at the juncture thereof.Type: GrantFiled: December 8, 1986Date of Patent: August 27, 1991Assignee: Hitachi, Ltd.Inventors: Akira Tanaka, Tadahiko Miyoshi
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Patent number: 5037784Abstract: The invention relates to a ceramic composition.It comprises at least one phase of a structure derived from that of tungsten tetragonal bronze and at least one phase of a structure derived from Perovskite.Application to the electrical and electronics industry.Type: GrantFiled: July 9, 1990Date of Patent: August 6, 1991Assignee: Centre National de la Recherche ScientifiqueInventors: Bernard Raveau, Gilbert Desgardin, Brahim Boufrou
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Patent number: 5032558Abstract: The invention relates to new ceramic electrostrictive compositions having superior electrical properties, a process for the preparation of the new electrostrictive compositions and applications for the new compositions. Specifically, a solid solution composition of lead magnesium niobate-lead titanate - (barium titanate or stronium titanate) has exhibited desirable electrostrictive properties. This composition shows a diminished dependence of dielectric constant on temperature.Type: GrantFiled: November 30, 1989Date of Patent: July 16, 1991Assignee: Martin Marietta CorporationInventors: Alex E. Bailey, Stephen R. Winzer, Audrey E. Sutherland, Andrew P. Ritter
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Patent number: 5030386Abstract: Iron is used as a dopant in barium titanate semiconductor ceramic material to increase the positive temperature coefficient of resistance thereof. By the use of about 0.010 to 0.500 weight percent silica and about 0.0075 to 0.0190 weight percent iron, room temperature resisitivity can be kept adequately low while the temperature coefficient of resistance is significantly increased.Type: GrantFiled: January 19, 1988Date of Patent: July 9, 1991Assignee: GTE Products CorporationInventors: Jay G. Saxton, Kazumasa Umeya
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Patent number: 5013695Abstract: A dielectric ceramic composition consisting essentially of barium oxide, titanium oxide, neodymium oxide and gadolinium oxide and which is expressed by the formula:aBaO-bTiO.sub.2 -c[(1-X)Nd.sub.2 O.sub.3 -XGd.sub.2 O.sub.3 ]wherein, 0.10.ltoreq.a.ltoreq.0.20, 0.65.ltoreq.b.ltoreq.0.75, 0.10.ltoreq.c.ltoreq.0.20, a+b+c=1 (a, b, and c are mole fractions), and O<X.ltoreq.0.4 (X is a mole fraction of Gd.sub.2 O.sub.3 based on the total amount of Nd.sub.2 O.sub.3 and Gd.sub.2 O.sub.3).Al.sub.2 O.sub.3 may be added in an amount of not more than 4 parts by weight to 100 parts by weight of the dielectric ceramic composition.Type: GrantFiled: May 22, 1989Date of Patent: May 7, 1991Assignee: Narumi China CorporationInventors: Hiroshi Kato, Shinsuke Yano, Toshio Nonomura, Susumu Nishigaki
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Patent number: 5011804Abstract: An improved ceramic dielectric composition for preparing multilayer ceramic structures for electronic devices and a method of enhancing the sinterability of such compositions at low firing temperatures by improving the distribution of zinc borate based sintering flux uniformly throughout the composition.Type: GrantFiled: February 28, 1990Date of Patent: April 30, 1991Assignee: E. I. Du Pont de Nemours and CompanyInventors: Horacio E. Bergna, Ian Burn
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Patent number: 4994421Abstract: In accordance with the process of the invention, there is formed electro-optical, barium lanthanum titanium niobate having a general uniform grain size of about 2 to about 20 microns. This material is formed using a raw material that comprises commercially available oxided particles of lanthanum, titanium, and niobium and carbonate of barium. The particles are calcined and then sintered under pressure, heat, and vacuumed to form a sintered mass. The mass is cooled in a controlled manner and then sliced to form wafers. The wafers are then heated in an oxidizing atmosphere to form the transparent electro-optical materials.Type: GrantFiled: December 2, 1988Date of Patent: February 19, 1991Assignee: Eastman Kodak CompanyInventor: Arun K. Mehrotra
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Patent number: 4988650Abstract: An auxiliary agent for sintering ceramics comprises a basic composition consisting essentially of (a) 5 to 40 mol % of at least two oxides selected from the group consisting of ZnO, SnO and MnO, the sum of the contents of ZnO and MnO being not less than 5 mol %, (b) 5 to 40 mol % of at least one metal oxide expressed by the general formula: RO where R is at least one element selected from the group consisting of Ba, Sr, Ca and Mg, and (c) 30 to 70 mol % of (Ti, Si)O.sub.2, the content of SiO.sub.2 being not less than 15 mol %. The auxiliary agent may contain at least one additive selected from the group consisting of Al.sub.2 O.sub.3, B.sub.2 O.sub.3, CuO, Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, Ga.sub.2 O.sub.3, GeO.sub.2, Y.sub.2 O.sub.3, ZrO.sub.2, WO.sub.3, MoO.sub.2, Fe.sub.2 O.sub.3, CoO, NiO, PbO and Bi.sub.2 O.sub.3.Type: GrantFiled: June 23, 1989Date of Patent: January 29, 1991Assignee: Murata Manufacturing Co., Ltd.Inventors: Hiroshi Takagi, Yukio Sakabe
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Patent number: 4987107Abstract: A ceramic composition for a reduction-reoxidation type semiconductive capacitor, comprising (A) barium titanate or barium titanate and strontium titanate, (B) titanium oxide, and (C) at least one oxide selected from the group consisting of the oxides severally of La, Ce, Nb, Nd, Dy, Y, Sb, W, and Ta in a molar ratio of 100:0.01.about.15:0.01.about.10 and further comprising (D) 0.001 to 1% by weight, based on the total amount of the compounds, (A), (B), and (C), of at least one oxide selected from the group consisting of the oxides severally of Cu, Zn, Al, Mg, and Mo and exhibiting a breakdown voltage of not less than 900 V, and insulation resistance of not less than 10.sup.10 .OMEGA., an electrostatic capacity per unit surface area of not less than 0.06 .mu.F/cm.sup.2, and a low dielectric loss, tan .delta., of not more than 2.0%.Type: GrantFiled: June 2, 1989Date of Patent: January 22, 1991Assignee: Nippon Oil & Fats Co., Ltd.Inventors: Kazuhito Narumi, Fumio Takeuchi, Michiaki Sakaguchi
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Patent number: 4987108Abstract: A dielectric paste for fabrication of multilayer ceramic substrates containing capacitive circuits. The paste comprises a dielectric powder composed of a dielectric material and a vitreous binder suspended in an organic vehicle. The dielectric material consists essentially of a composition expressed by the general formula:{(Ba.sub.1-x-y-z Sr.sub.x Ca.sub.y Mg.sub.z)O}.sub.m .multidot.(Ti.sub.1-u Zr.sub.u)O.sub.2wherein x, y, z, u and m take values within the following respective ranges: 0.ltoreq.x<0.30, 0.ltoreq.y<0.30, 0.ltoreq.z<0.05, 0.ltoreq.u<0.25, 1.ltoreq.m<1.03, and the vitreous binder consists essentially of a composition expressed by the general formula:.alpha.Li.sub.2 O.multidot..beta.BaO.multidot..gamma.B.sub.2 O.sub.3 .multidot.(1-.alpha.-.beta.-.gamma.)SiO.sub.2wherein .alpha., .beta. and .gamma. are molar ratios of the respective ingredients and take values within the following respective ranges: 0.ltoreq..alpha.<0.25, 0.1.ltoreq..beta.<0.5, 0.1<.gamma.<0.5, and 0.Type: GrantFiled: March 9, 1988Date of Patent: January 22, 1991Assignee: Murata Manufacturing Co., Ltd.Inventors: Hiroshi Takagi, Yoshiaki Mori, Hiroji Tani, Yukio Sakabe
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Patent number: 4978646Abstract: This invention relates to the production of ceramic materials which exhibit a dielectric constant in excess of 105, when measured at room temperature, and a small temperature coefficient of capacitance across the temperature range of -55.degree. to 125.degree. C., when compared to the capacitance measured at room temperature, which material has a composition encompassed within one of the following general formulae:(Bi.sub.2 O.sub.2).sup.2+ (A.sub.m-1 B.sub.m O.sub.3m+1).sup.2- ; (I)(Bi.sub.2 O.sub.2).sup.2+ (A.sub.m-1 B.sub.m Zr.sub..beta. O.sub.3m+.delta.+1).sup.2- ; and (II)(Bi.sub.2 O.sub.2).sup.2+ (A.sub.m-1 B.sub.m Mn.sub..gamma. O.sub.3m+.delta.+1).sup.2- (III)(Bi.sub.2 O.sub.2).sup.2+ (A.sub.m-1 B.sub.m Zr.sub..beta. Mn.sub..gamma. O.sub.3m+.delta.+1).sup.Type: GrantFiled: March 3, 1989Date of Patent: December 18, 1990Assignee: Corning IncorporatedInventors: Pronob Bardhan, Roger F. Bartholomew, Donald M. Trotter, Jr., Chyang J. Yu
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Patent number: 4968649Abstract: The present invention provides a dielectric ceramic composition for use in a high-frequency range represented by the general formula (1-x)Ba.sub.1- y(Zn.sub.1/3, Ta.sub.2/3)O.sub.3 +xBa.sub.1-y ZrO.sub.3. In the formula, y is 0.004.ltoreq.y.ltoreq.0.013 and x is the amount of substitution of Ba.sub.1-y ZrO.sub.3 and 0<x.ltoreq.0.06. This composition is prepared by weighing raw materials so that the mixing ratio of Ba is slightly smaller than that of the stoichiometric composition, calcining the resultant mixture to prepare a calcination product, grinding the calcination product through only dry process without conducting wet pulverization, molding the resultant powder, and sintering the molded product at 1600.degree. to 1700.degree. C. for 1 to 10 hr.Type: GrantFiled: December 8, 1989Date of Patent: November 6, 1990Assignee: Fuji Electrochemical Co., Ltd.Inventors: Michiaki Tsurumi, Kenji Fujimoto, Kazuaki Endo
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Patent number: 4960739Abstract: A dielectric material for use in a microwave resonator comprises 78.1 mol % of TiO.sub.2, 15.7 to 17.8 mol % of BaO, 4.00 ml % of SnO.sub.2 and at least one of 0.1 to 1.0 mol % of SrO and 0.1 to 1.2 mol % of CaO.Type: GrantFiled: February 8, 1990Date of Patent: October 2, 1990Assignee: Sumitomo Special Metal Co., Ltd.Inventor: Keisuke Kageyama
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Patent number: 4959089Abstract: A process for preparing a tetragonal barium titanate film with a thickness of from about 0.1 to about 1.5 millimeters is disclosed.In the first step of this process, a mixture of a barium compound, a titanium compound, and a boron oxide glass former is provided in a specified ratio.The reaction mixture is melted at a temperature of 1300-1400 degrees centigrade and then rapidly quenched in form glass. The glass is then place upon a polycrystalline isostructural substrate, and the glass/substrate assembly is then remelted and, thereafter, subjected to a temperature of from 950 to 1,050 degrees centigrade for from about 25 to about 60 minutes.Type: GrantFiled: May 3, 1988Date of Patent: September 25, 1990Assignee: Alfred UniversityInventors: Atit Bhargava, Robert L. Snyder
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Patent number: 4956320Abstract: A positive temperature coefficient semiconductor ceramic is prepared by adding from 0.2 to 12 mole % of silicon monoxide to a barium titanate family semiconductor ceramic which has been made into a semiconductor by the addition of a trace amount of a semiconductor agent.Type: GrantFiled: February 13, 1989Date of Patent: September 11, 1990Assignee: Kurabe Industrial Co., Ltd.Inventors: Masahiro Asakura, Akihiko Igawa
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Patent number: 4939108Abstract: The present invention provides ceramic compositions for preparing multi-layer capacitors, having high dielectric constants between about 4900 and 5400, dissipation factors below about 2.0%, high insulation resistance capacitance products and stable temperature coefficient characteristics, by a process of mixing a major oxide component with one or more precipitated dopant components.Type: GrantFiled: November 2, 1988Date of Patent: July 3, 1990Assignee: TAM Ceramics, Inc.Inventor: Terrence C. Dean
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Patent number: 4925817Abstract: A non-reducible dielectric ceramic composition comprising barium titanate as the main component, which contains an additive expressed by the formula Ba.sub..alpha. Ca.sub.1-.alpha. SiO.sub.3 (0.43.ltoreq..alpha..ltoreq.0.62) in an amount of from 0.1 to 6 mol parts per 100 mol parts of the barium titanate.Type: GrantFiled: July 7, 1989Date of Patent: May 15, 1990Assignee: TDK CorporationInventors: Masaaki Ikeda, Wataru Takahara
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Patent number: 4916261Abstract: A circuit substrate comprises a sintered oxide body of barium, tin and boron as an insulating body which is able to be fired at a temperature less than 1300.degree. C. The circuit substrate is further improved in moisture resistance by containing titanium or securing substantially the composition of BaSn(BO.sub.3).sub.2.Type: GrantFiled: September 7, 1984Date of Patent: April 10, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Truong D. Thanh, Nobuo Iwase
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Patent number: 4904411Abstract: Slurries or suspensions for forming sintered ceramic or metallic articles are described as having a high volume fraction of sinterable particles, at least 55% by volume. while the slurries maintain a pourable viscosity, such as not more that 2000 cPs at 100 s.sup.-1 ; the slurries can be dilatant and/or pseudoplastic. The slurries are prepared by using specific families of dispersants; namely acrylic acid-based polymeric polyelectrolytes, polyethylene imine-based polyelectrolytes, and coupling agents from the subfamilies of oxy-silane esters and phosphate esters. Fabrication of the compositions includes milling under high energy and the addition of at least a portion of the particles in a step-wise manner.Type: GrantFiled: September 9, 1988Date of Patent: February 27, 1990Assignee: Ceramics Process Systems Corp.Inventors: Bruce E. Novich, Mark A. Occhionero, Richard L. Pober
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Patent number: 4898844Abstract: A ceramic includes a dielectric ceramic body that is made by mixing powders of two barium titanate compositions of widely disparate Curie temperature with a minor quantity of a borate flux and a sintering-inhibitor such as titania or bismuth oxide. A body is formed of this start powders mixture. Upon sintering to maturity at about 1100.degree. C., the capacitor body becomes only partially co-reacted and has a dielectric constant around 2000 that varies no more than about 15% over a board operating temperature range. These properties are not a strong function of sintering conditions leading to good control at manufacturing.Type: GrantFiled: July 14, 1986Date of Patent: February 6, 1990Assignee: Sprague Electric CompanyInventors: Galeb H. Maher, Susan E. Stefanik
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Patent number: 4897249Abstract: A filtered solution of barium hydroxide octahydrate reacted with an aqueous solution of boric acid to provide hydrated .gamma. barium borate having a barium to boron ratio of 1:2 and having fine particle size. The hydrated .gamma. barium borate was converted to the anhydrous .gamma. form at about 300.degree. to 400.degree. C. Further heating to about 600.degree. to 800.degree. C. converted the product to .beta.-BaB.sub.2 O.sub.4. The conversion to the .beta.-form is preferably during sintering of a ceramic dielectric composition to which the .gamma.-BaB.sub.2 O.sub.4 has been added as a flux.Type: GrantFiled: April 3, 1989Date of Patent: January 30, 1990Assignee: Sprague Electric CompanyInventors: Sidney D. Ross, Manuel Finkelstein
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Patent number: 4897219Abstract: It is a voltage-dependent non-linear resistance ceramic composition comprising SrTiO.sub.3 as host material, Dy.sub.2 O.sub.3 or Dy.sub.2 O.sub.3 and Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.5 as accelerating agent for semiconductorization, thereby changing crystal to a low resistance, and changing crystal boundary to a high resistance.In case Dy.sub.2 O.sub.3 or Dy.sub.2 O.sub.3 and Nb.sub.2 O.sub.5 are used as the accelerating agent for semiconductorization, one kind or more selected from the group consisting of Na, K, Ca, Cd, In, Ba, Pb, Ag, Ce, La, Sc, Y, Cs, Au, Mg, Zr, Sn, Sb, W, Bi, Ni, Fe, Ga, Pt, Tl, Al, Si, Be, Li, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf and Ru. Alternatively, in case Ta.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.Type: GrantFiled: November 7, 1988Date of Patent: January 30, 1990Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiichi Noi, Akihiro Takami, Kazuhide Ebine, Kimiko Kumazawa
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Patent number: 4889837Abstract: A semiconductive ceramic composition for a boundary insulation type semiconductive ceramic capacitor capable of causing the capacitor to exhibit increased dielectric constant, satisfactory frequency and temperature characteristics, and decreased dielectric loss. The composition includes a SrTiO.sub.3 base component and a minor component consisting of CaTiO.sub.3, Y.sub.2 O.sub.3 and Nb.sub.2 O.sub.5. The composition may further contain MnO and SiO.sub.2, which contribute to an increase in insulation resistance of the capacitor and enlargement of an appropriate range of a (SrO+CaO)/TiO.sub.2, respectively. Also, a composition includes a SrTiO.sub.3 base component and a minor component consisting of CaTiO.sub.3, BaTiO.sub.3, Y.sub.2 O.sub.3 and Nb.sub.2 O.sub.5.Type: GrantFiled: August 21, 1987Date of Patent: December 26, 1989Assignee: TDK CorporationInventors: Shuichi Ono, Shuichi Itagaki, Masahiro Yahagi
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Patent number: 4882305Abstract: 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: GrantFiled: October 9, 1987Date of Patent: November 21, 1989Assignee: TAM Ceramics, Inc.Inventors: Mike S. H. Chu, Charles E. Hodgkins, Terence C. Dean
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Patent number: 4866017Abstract: A dielectric ceramic composition of matter consisting essentially of a range of composition wherein the composition formula representsxBaO.yNd.sub.2 O.sub.3.zTiO.sub.2.wBi.sub.2 O.sub.3wherein 0.110.ltoreq.x.ltoreq.0.170, 0.120.ltoreq.y.ltoreq.0.180, 0.630.ltoreq.z.ltoreq.0.685, 0.020.ltoreq.w.ltoreq.0.090, and x+y+z+w=1. The composition of matter provides the advantage that it is high in dielectric constant, small in dielectric loss in high frequency and small in change with respect to temperature of resonance frequency.Type: GrantFiled: February 12, 1988Date of Patent: September 12, 1989Assignee: Kyocera CorporationInventor: Takashi Okawa
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Patent number: 4863883Abstract: The present invention relates to a variety of dispersible doped multi-component BaTiO.sub.3 based powder compositions. The primary particles of each of the products are substantially spherical, have sizes in the range of 0.05 to 0.4 microns and have narrow size distributions. Further, the compositions of the primary particles, forming each powder, are comparable. The amount of dopant oxide or oxides contained in the powder composition ranges from between greater than 1 to 10 mole percent. Regardless of the dopant or dopants utilzied, all the powder compositions of the present invention are identified by the same unique morphological characteristics.Type: GrantFiled: August 23, 1988Date of Patent: September 5, 1989Assignee: Cabot CorporationInventors: Jameel Menashi, Robert C. Reid, Laurence P. Wagner
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Patent number: 4861736Abstract: A semiconductive ceramic composition for a reduction reoxidation type semiconductive ceramic capacitor capable of increasing capacitor, dielectric strength of the capacitor and improving temperature characteristics of the capacitor. The composition includes a BaTIO.sub.3 base component and a minor component consisting of Nb and Ce. Nb and Ce are present in amounts of 0.2 to 3.0 mol % on Nb.sub.2 O.sub.5 and CeO.sub.2 bases. Addition of Co and the like increases insulation resistance and D.C. breakdown voltage of the capacitor and further improves temperature characteristics of the capacitor.Type: GrantFiled: August 4, 1987Date of Patent: August 29, 1989Assignee: TDK CorporationInventors: Shuichi Ono, Masahiro Yahagi, Shuichi Itagaki, Nobuaki Kikuchi