Abstract: A piezoelectric ceramic composition excellent in all of the electric property Qmax, heat resisting properties and temperature characteristics of oscillation frequencies is provided. The piezoelectric ceramic composition comprises a phase mainly comprising lead zirconate titanate having a perovskite structure and an Al-containing phase. In the piezoelectric ceramic composition, the main component preferably comprises Mn and Nb, and is preferably represented by a composition formula of Pb?[(Mn1/3Nb2/3)xTiyZrz]O3 (wherein 0.97???1.01, 0.04?x?0.16, 0.48?y?0.58, 0.32?z?0.41).

Abstract: The present invention has an object to provide piezoelectric ceramics containing no lead, having a high Curie point, and further, having excellent piezoelectric properties, particularly large Qmax. The piezoelectric ceramics contain, as a main component, a bismuth layer-structured compound having (MII1-xLnx)Bi4Ti4O15 crystals (MII is an element selected from Sr, Ba, and Ca, Ln is an element selected from lanthanoids, and x is within a range of 0<x?0.5) and further contain, as secondary components, at least one of Mn oxide and Co oxide, and lanthanoid, wherein the lanthanoid being the secondary component is contained within a range of 0.02 to 0.12 wt % in terms of oxide thereof.

Abstract: A piezoelectric ceramics having ceramic particles, wherein said ceramic particles comprises bismuth layer compound containing at least Sr, Ln (note that Ln is a lanthanoid element), Bi, Ti and O and including MIIBi4Ti4O15 type crystal (MII is an element composed of Sr and Ln) as a main component, and an oxide of Mn as a subcomponent; and an average particle diameter by the code length measuring method is 0.8 to 4.7 ?m: by which it is possible to provide piezoelectric ceramics having a large Qmax in a third harmonic mode of thickness vertical vibration in a relatively high frequency band (for example, 16 to 65 MHz), a resonator an other piezoelectric element comprising the piezoelectric ceramics as a piezoelectric substance thereof.

Abstract: A piezoelectric ceramic composition excellent in heat resisting properties is provided. In the piezoelectric ceramic composition including a perovskite compound containing Pb, Zr and Ti as main components, the piezoelectric ceramic composition is made to include Cr as an additive from 0.025 to 0.250 wt % in terms of Cr2O3. In the piezoelectric ceramic composition of the present invention, ?k15 (here, ?k15 is the rate of change in electromechanical coupling factor k15, caused by external thermal shock), of the piezoelectric ceramic composition can be controlled to 3.0% or less in absolute value.

Abstract: There is provided a resonator having a piezoelectric ceramic resonator which has excellent free-fall resistance. The resonator comprises a piezoelectric ceramic resonator 2 with a vibrating electrode formed, and a substrate 3 which supports the piezoelectric ceramic resonator 2, wherein the piezoelectric ceramic resonator 2 satisfies the condition of U?0.88×H+20.28, wherein U=maximum elastic energy (kJ/m3) per unit volume, and H=drop height (m) (H>1). The present invention can be applied to a resonator 1, wherein the substrate 3 has terminal electrodes 31, 32, and the piezoelectric ceramic resonator 2 is in electrical continuity with the vibrating electrode and is supported on the substrate 3 at both ends via a conductive stator 4.

Abstract: The present invention has an object to provide piezoelectric ceramics containing no lead, having a high Curie point, and further, having excellent piezoelectric properties, particularly large Qmax. The piezoelectric ceramics contain, as a main component, a bismuth layer-structured compound having (MII1-xLnx)Bi4Ti4O15 crystals (MII is an element selected from Sr, Ba, and Ca, Ln is an element selected from lanthanoids, and x is within a range of 0<x?0.5) and further contain, as secondary components, at least one of Mn oxide and Co oxide, and lanthanoid, wherein the lanthanoid being the secondary component is contained within a range of 0.02 to 0.12 wt % in terms of oxide thereof.

Abstract: A piezoelectric ceramic composition which has a large electromechanical coupling factor and is excellent in heat resisting properties is provided. As additives, Cr, Al and Si are contained together in the piezoelectric ceramic composition including a perovskite compound which contains Pb, Zr and Ti as main components. Preferably, Cr, Al and Si are respectively contained in a content of 0.05 to 0.50 wt % in terms of Cr2O3, in a content of 0.005 to 1.500 wt % in terms of Al2O3, and in a content of 0.005 to 0.100 wt % in terms of SiO2. By simultaneously including these three elements and setting the contents thereof to fall within the above mentioned ranges, the electromechanical coupling factor kt can be 30% or more, and ?Fr, which is the rate of change in resonant frequency Fr between before and after application of an external thermal shock, can be 0.5% or less in absolute value.

Abstract: There are provided steps of polarizing a ceramic composition including a perovskite compound containing Pb, Zr, Ti and Mn as main components and a heat treatment step for keeping the polarized ceramic composition within a temperature range lower than Tc (Tc denoting the Curie temperature of the ceramic composition) for 1 to 100 minutes.