Matsushita Electric Industrial Co., Ltd.

Syunichiro Kawashima

Masamitsu Nishida

Hiromu Ouchi

Ichiro Ueda

Hideaki Adachi

Osamu Inoue

Kentaro Setsune

Yo Ichikawa

Shigeru Hayakawa

Junichi Kato

Kojiro Okuyama

Koichi Kugimiya

Yoshihiro Matsuo

Koji Shimoyama

Seiji Adachi

Yoichiro Yokotani

Kouichi Kugimiya

A surface acoustic module is stable, and its operation frequencies can be varied with high precision. A method of manufacturing the surface acoustic module prevents the module's electrodes from being broken during separation of a sheet of modules into individual components. The surface acoustic module includes electrodes for transmitting and receiving a surface acoustic wave, a surface acoustic wave transmitting substrate, a high resistance thin film, and a thin film for differentiating the transmission velocity of a surface acoustic wave at the high resistance thin film from that at the substrate. The method includes the steps of forming a metallic film on a sheet of the surface acoustic wave transmitting substrate, of forming the electrodes on the metallic film, and of irradiating light or the like to the metallic film so as to increase the film's resistivity.

Method of manufacturing surface acoustic ware modules

Method of manufacturing a surface acoustic wave module

Surface acoustic wave module with thin film for wave transmission

The present invention provides dielectric ceramics with less variation of temperature coefficient at a resonant frequency due to heating history during the sintering of ZrTiO.sub.4 and ZrO.sub.2 --SnO.sub.2 --TiO.sub.2 ceramics, and having a high unloaded Q value and a high dielectric constant, and a temperature coefficient at a resonant frequency which is widely variable as desired, and dielectric resonators using the dielectric ceramics which have a high unloaded Q value and a strong electrode layer. The main components of the dielectric ceramics may be expressed by the formula: xZrO.sub.2 --yTiO.sub.2 --zA.sub.(1+u)/3 B.sub.(2-u)/3 O.sub.2 wherein A denotes at least one component selected from the group (A) consisting of Mg, Co, Zn, Ni and Mn, B denotes at least one component selected from the group (B) consisting of Nb and Ta, and x, y, z and u (x, y and z are molar fractions and u is a value within the range from 0 to 1.90) have the relation of x+y+z=1.0, 0.10.ltoreq.x.ltoreq.0.60, 0.20.ltoreq.y.ltoreq.0.60, 0.01.ltoreq.z.ltoreq.0.70. The main component may include, as accessory components, at least one component selected from the group (C) consisting of Ba, Sr, Ca, Cu, Bi and W at 0.005 to 7.000% by weight of the entire weight of the ceramic.

Dielectric ceramic compositions and dielectric resonators

An oxide superconductive material comprising constituent elements mainly composed of ABiCuO in which A comprises at least one element of alkaline earth metals, and having a C-plane orientation, and a method of orienting such superconductive materials by hot extrusion from a rectangular nozzle.

Bi, alkaline earth, Cu extruded oxide superconductive material having a

The present invention provides a process for producing powder of complex perovskite type compounds by using metal alkoxides. In the prior art, methods were known for synthesizing crystalline powder of simple perovskite type compounds such as BaTiO.sub.3. According to the conventional methods, however, when synthesizing a complex perovskite type compound having two atoms of different valences at the B site of perovskite structure by hydrolyzing metal alkoxides, there could be obtained only amorphous powder, and for crystallizing it, heating to a temperature of around 600.degree. to 800.degree. C. was necessary. According to the process of this invention, it is possible to synthesize the crystalline complex perovskite type compounds at a low temperature of around 100.degree. C., which is 500.degree. to 700.degree. C. lower than the temperature required in the conventional methods, by adjusting the amount of water added according to the type of the solvent used and controlling the reaction temperature at a specified level or higher.

Process for the preparation of complex perovskite type compounds

A method for producing crystalline complex perovskite compounds from starting compounds of at least one metal such as Ca, Ba or Sr, at least one metal such as Mg, Zn, Ni or Co and at least one metal such as Ta or Ni. The respective compounds are selected from oxides, hydroxides, hydrous oxides, and water-soluble organic compounds and inorganic salts of the respective metals. The water-soluble organic compounds and inorganic salts are capable of yielding metal oxides, hydroxides and hydrous oxides by hydrolysis. These starting compounds are heated at certain temperatures in an alkaline aqueous solution to obtain the perovskite compound at significantly low reaction temperatures of at least 95.degree. C. Prior to the heating, the starting compounds may be treated in the alkaline aqueous solution at temperatures lower than 95.degree. C. to form a uniformly mixed amorphous phase of the compounds and then heated.

Method for producing crystalline complex perovskite compounds

A dielectric ceramic composition consisting essentially of:

Dielectric ceramic compositions

A dielectric ceramic composition consisting essentially of a solid solution represented by the formula:

Dielectric ceramics

A dielectric ceramic consisting essentially of at least 88 weight % of a main component and up to 12 weight % of stannic oxide (SnO.sub.2), said main component consisting essentially of 34.5 to 82 weight % of titanium oxide (TiO.sub.2), 9 to 63 weight % of Praseodymium oxide (Pr.sub.6 O.sub.11) and 2.5 to 23.5 weight % of barium oxide (BaO), at most 95 weight % of said praseodymium oxide being replaceable by neodymium oxide (Nd.sub.2 O.sub.3). It exhibits large dielectric constant and low microwave loss with large temperature-stability for resonant frequency and it is suitable for use as dielectric resonators, electrical filters, substrates, etc.

A dielectric ceramic consisting essentially of a solid solution represented by the formula:

A dielectric ceramic having a composition expressible by (1-w) (xBaO.multidot.yNa.sub.2 O.multidot.zNb.sub.2 O.sub.5)+wMeO.multidot.ZrO.sub.2 wherein Me denotes Ca or Sr, 0.593.ltoreq.x.ltoreq.0.762, 0.04.ltoreq.y.ltoreq.0.13, 0.174.ltoreq.z.ltoreq.0.32, x+y-z=1, and 0&lt;w.ltoreq.0.95. It exhibits large dielectric constant and low microwave loss with high temperature-stability for resonant frequency and is suitable for use as dielectric resonators, electrical filters, substrates, etc.

A piezoelectric ceramic elements obtained by hot-press sintering a composition expressed by the formula:

Method for preparing piezoelectric ceramics

Calcined material having a composition including at least two of the components 3BaO.ZnO.Nb.sub.2 O.sub.5, 3BaO.ZnO.Ta.sub.2 O.sub.5, 3BaO.MgO.Nb.sub.2 O.sub.5, and 3BaO.MgO.Ta.sub.2 O.sub.5 and produced under optimum processing conditions as disclosed is employed for obtaining ceramics having low microwave loss with large dielectric constant and suitable for use as dielectric resonators, electrical filters, substrates, etc.

Low microwave loss ceramics and method of manufacturing the same

A method of making an electrooptical system including a transparent ferroelectric ceramic element which possesses memory in that a birefringence corresponding to an applied electric field remains after the field is removed. The electrooptical element is hot-pressed from a family of materials which comprises solid solution of the ternary system, lead magnesium niobate-lead titanate-lead zirconate, and the hot-pressed material may additionally contain a small amount of lanthanum oxide (La.sub.2 O.sub.3).

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Nishinomiya, Japan

Syunichiro Kawashima