Abstract: A piezoelectric ceramic is provided which has a very low loss and superior workability in micro-fabrication. The piezoelectric ceramic contains at least Pb, Mn, Nb, Ti and Zr as primary metal components, in which, when the composition of the piezoelectric ceramic is represented by the formula Pbx{(MnaNbb)yTizZr(1−Y−z)}O3, the x, y, z, a, and b are, on a molar basis, such that 0.95≦x≦0.995, 0.055≦y≦0.10, 0.40≦z≦0.55, 2.01≦b/a≦2.40, and a+b=1. In addition, the average grain diameter of the sintered piezoelectric ceramic is about 2 &mgr;m or less.

Abstract: A piezoelectric ceramic material is provided which can form a sintered piezoelectric ceramic compact having a low electromechanical coupling coefficient, a low resonant resistance and a low temperature dependence of the resonant frequency. The piezoelectric ceramic material is a solid solution having a primary component composed of PbTiO3, PbZrO3 and Pb(MaXMdY)O3, in which Ma is at least one bivalent element or trivalent element, and Md is at least one pentavalent element or hexavalent element, and the ratio X/Y of the Ma content X to the Md content Y is larger than the stoichiometric ratio. Preferred is Ma being Mn, Md being at least one of Nb, Sb, Ta and W, and when the contents of Mn, Nb, Sb, Ta and W are represented by A, B, C, D and E, respectively, 0.525≦A/(B+C+D+2E)≦1, and about 20 mole percent or less of the element Pb being replaced by at least one of Ca, Ba, Sr and La.

Abstract: A piezoelectric ceramic material able to form a piezoelectric ceramic sintered body having such characteristics as a small electromechanical coupling coefficient, small resonant resistance and small temperature dependency of the resonant frequency that is required for designing a narrow-band filter is represented by principal component of the general formula of (PbaSrb)(ZrcTidMneNbf)O3 and having a composition satisfying the following relations of 0.93≦a≦1.01, 0.01≦b≦0.04, 0.37≦c≦0.47, 0.48≦d≦0.58, 0.0105≦e≦0.06, 0.02≦f≦0.06 and 1.05≦2e/f≦2, and comprising sub-components of about 0.003% to 0.1% by weight of each of SiO2 and Al2O3 relative to the principal component.

Abstract: 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 10 of the present invention has a metal plate 12. Formed on the metal plate 12 is a piezoelectric ceramic 14. Further, formed on the piezoelectric ceramic 14 is an electrode 16. 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 PbA[(TixZr1-x)a(SnyCr1-y)bSbc]O3 has been displaced by La, wherein 0.94≦A≦1.02, 0.46≦x≦0.51, 0.01≦y≦0.5, 0.01≦b≦0.03, 0.01≦c≦0.04,a+b+c=1.

Abstract: A surface acoustic wave device includes a piezoelectric substrate, and an interdigital transducer provided on the piezoelectric substrate, wherein the piezoelectric substrate includes at least two piezoelectric ceramic layers made of a polycrystalline material. The at least two piezoelectric ceramic layers are stacked so that electrical characteristics and mechanical characteristics thereof vary in a direction that is substantially perpendicular a surface of the piezoelectric substrate upon which the at least two ceramic piezoelectric layers are stacked.

Abstract: Provided is a piezoelectric ceramic composition containing a lead titanate which has excellent temperature stability of the resonance frequency, and is suitable for application in a filter, a vibrator or the like, and a piezoelectric element using the piezoelectric ceramic composition. A piezoelectric substrate comprising a ceramic material containing PbTiO.sub.3 is provided with vibrating electrodes on the front and rear surfaces. The ceramic material containing PbTiO.sub.3 contains not less than about 0.1% by weight or more than about 3.0% by weight of Mn based on MnCO.sub.3 as the subcomponent in the main component having a composition satisfying 0.02.ltoreq.x.ltoreq.0.16 and 0.15.ltoreq.y.ltoreq.0.50 of the general formula Pb.sub.1-1.5x Nd.sub.x [(In.sub.1/2 Nb.sub.1/2).sub.y Ti.sub.1-y ]O.sub.3.

Abstract: The present invention provides a method for producing a piezoelectric ceramic element in which evaporation of Pb contained in a piezoelectric material is prevented and which allows use of inexpensive metal as an electrode material without substantial deterioration of piezoelectric characteristics. The method includes the steps of (1) mixing at least oxides of Pb, Zr, Ti, Cr and Nb; (2) calcining the mixture; (3) crushing the calcined product and adding a Cu component in an amount of about 0.05-3.0 wt. % calculated as CuO; (4) adding a binder to the Cu-component-containing mixture; (5) molding the binder-containing mixture; (6) firing the molded product at 1100.degree. C. or less to produce a sintered product; and (7) forming electrodes on surfaces of the sintered product, the sintered product containing a primary component represented by the formula:Pb.sub.a [(Cr.sub.x Nb.sub.(1-x)).sub.y Zr.sub.(1-b-y) Ti.sub.b ]O.sub.3wherein 0.95.ltoreq.a.ltoreq.1.05; 0.40.ltoreq.b.ltoreq.0.55; 0.10.ltoreq.x.ltoreq.0.

Abstract: A Mo side component is added to the essential component of a piezoelectric ceramic composition containing Pb, Zr, Ti and O, in an amount of from about 0.06% by weight to about 5.0% by weight, in terms of MoO.sub.3, relative to the amount of the essential component. Preferably, the side component is added to the calcined essential component, and the resulting mixture is fired to give a sintered piezoelectric ceramic composition. The addition of the side component improves the low-temperature sinterability of the piezoelectric ceramic composition without worsening the piezoelectric characteristics of the composition.