Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Tomoyuki Ogawa

Katsuhiro Horikawa

Akira Ando

Masahiko Kimura

Toshikatsu Hisaki

A monolithic piezoelectric part capable of yielding a high piezoelectric d constant and suppressing reduction in reliability such as deterioration in insulation resistance can be obtained by a method for manufacturing a monolithic piezoelectric part wherein a piezoelectric ceramic body is formed of a perovskite compound oxide expressed by the general formula of ABO, and the molar quantity of the A site component, Pb, is reduced by about 0.5 mol % to 5.0 mol % from that of the stoichiometric composition, ceramic raw materials are combined so that the average valence of the B site component is greater than quadrivalent, which is the same as the stoichiometric composition, to synthesize the ceramic powdered raw material, which is processed subsequently to fabricate a layered article, and the layered article is subjected to sintering processing within an atmosphere wherein the oxygen concentration is about 5% or less but more than 0% by volume.

Manufacturing method for monolithic piezoelectric part, and monolithic piezoelectric part

A piezoelectric ceramic composition is expressed by the formula Pb &lsqb;&lcub;Ni Nb &rcub; Ti Zr &rsqb;O . The B site variables x, y, and z lie in a predetermined region in a ternary diagram. The Ni&mdash;Nb molar proportion variable satisfies the relationship 0.85&lE;w<1.00. The Pb molar content &agr; is reduced from the stoichiometric ratio to a value satisfying the relationship 0.950&lE;&agr;&lE;0.995. At least one element selected from the group consisting of Sr, Ca, and Ba may be substituted for about 10 mol percent of the Pb.

Piezoelectric ceramic composition and piezoelectric element

A piezoelectric ceramic composition contains a compound containing Na, Li, Nb and O, and having a perovskite structure, as a main component. The main component has a crystal phase in a semi-stable state at room temperature, such crystal phase originally not being stable at room temperature but being stable at a higher temperature.

Piezoelectric ceramic composition, piezoelectric ceramic element, and method for manufacturing the piezoelectric ceramic composition

A piezoelectric buzzer formed by using a piezoelectric ceramic having both a higher heat resistance and a higher piezoelectric characteristics than those of a conventional product. The piezoelectric buzzer,of the present invention has a metal plate,Formed on the metal plate,is a piezoelectric ceramic,Further, formed on the piezoelectric ceramic,is an electrode,The piezoelectric composition forming the piezoelectric ceramic is a piezoelectric ceramic composition characterized in that about 0.2 to 2 mol % of the Pb atoms of a lead zirconate titanate (PZT) represented by the composition formula Pb,&lsqb;(Ti,Zr,),(Sn,Cr,),Sb,&rsqb;O,has been displaced by La, wherein 0.94&lE;A&lE;1.02, 0.46&lE;x&lE;0.51, 0.01&lE;y&lE;0.5, 0.01&lE;b&lE;0.03, 0.01&lE;c&lE;0.04,a&plus;b&plus;c&equals;1.

Piezoelectric ceramic composition, buzzer and actuator using the same

The present invention provides a piezoelectric ceramic composition which predominantly comprises a composition represented by the following formula :

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Toyama-ken, Japan

Tomoyuki Ogawa