Kyocera Corporation

Takashi Okawa

Nobuo Yokoe

Nobuyoshi Fujikawa

Kazuyoshi Yamashita

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.

Dielectric ceramic composition

A dielectric ceramic composition of matter consisting essentially of a range of composition wherein the composition formula represents

Dielectric ceramic composition of matter

Disclosed is a dielectric ceramic material having a chemical composition represented by the formula Sr(Ni.sub.1/3 Nb.sub.2/3)O.sub.3 or (1-x)Sr(Ni.sub.1/3 Nb.sub.2/3)O.sub.3.xBaTiO.sub.3 in which x is a positive number of up to 0.3 and also having a perovskite structure. This dielectric material has a small dielectric loss and a large dielectric constant, and the temperature coefficient of the resonance frequency can be controlled to a small value within a certain range. The dielectric ceramic material is valuably used for microwave dielectric ceramics.

In a multilayer ceramic capacitor comprising internal electrodes of an Ag-Pd alloy, by incorporating 0.05 to 0.7%, by weight of Ag into a ceramic dielectric layer, the equivalent series resistance can be reduced and the capacitance can be increased. Incorporation of Ag in the dielectric layer can be accomplished by adding Ag.sub.2 O into a green sheet of the dielectric material in advance or by firing a green sheet of the dielectric material in a powder containing Ag.sub.2 O.

Multilayer ceramic capacitor and process for preparation thereof

Disclosed is a dielectric ceramic material comprising lanthanum magnesiumtitanate having a perovskite structure. The lanthanum magnesiumtitanate is preferably used in the form of a composition of the lanthanum magnesiumtitanate and calcium titanate as the dielectric ceramic material. The dielectric ceramic material has a small dielectric loss and a large dielectric constant, and the temperature coefficient of the resonance frequency can be controlled to a small value within a certain range. This dielectric material is valuable as a microwave resonator.

Dielectric ceramic material

A dielectric ceramic composition prepared by adding 0.1 to 1.3% of B.sub.2 O.sub.3, 1.0 to 3.0% of SiO.sub.2 and 0.5 to 3.0% of ZnO to a composition comprising 18.0 to 27.0% of BaTiO.sub.2, 31.6 to 36.3% of Nd.sub.2 O.sub.3, 27.6 to 35.5% of TiO.sub.2, 2.5 to 8.1% of Bi.sub.2 O.sub.3 and 5.6 to 9.0% of Pb.sub.3 O.sub.4, all percentages being by weight. This dielectric composition has a high dielectric constant and a temperature coefficient controlled within a narrow range and can be fired at relatively low temperatures. Because of these properties, it is used as a multilayer ceramic capacitor in combination with an electrode composed of an Ag-Pd alloy containing a major amount of Ag.

Dielectric composition and laminated capacitor

Disclosed is a dielectric material composition having the following composition formula:

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Kokubu, Japan

Takashi Okawa