Murata Manufacturing Co., Ltd.

Kosuke Shiratsuyu

Masahiko Kimura

Atsushi Sakurai

Xiao-min Li

Hirozumi Ogawa

Akira Ando

Kunisaburo Tomono

Nobuyuki Wada

Takuya Sawada

Toshikazu Takeda

Kiyoshi Hase

Kohichi Hayashi

Kenichi Nada

A method for manufacturing a piezoelectric element that includes a piezoelectric ceramic body containing an internal electrode. The piezoelectric ceramic body is mainly made of a perovskite complex oxide containing an alkali metal niobate-based compound containing at least one element selected from among K, Li, and Na. The internal electrode is made of a base metal material, such as Ni or Cu. The piezoelectric element is produced by co-sintering the internal electrode and the piezoelectric ceramic body in a reducing atmosphere.

Method of manufacturing a piezoelectric element

A piezoelectric ceramic composition includes a main component represented by general formula {(PbCaSr) {Ti(NiNb)}O}, wherein 0&#x2266;x&#x2266;0.2 (preferably 0&#x2266;x&#x2266;0.15), 0&#x2266;y&#x2266;0.2 (preferably 0&#x2266;y&#x2266;0.1), 0.05&#x2266;x+y&#x2266;0.2, and 0.02&#x2266;z&#x2266;0.1. Furthermore, a Mn component is preferably present in an amount of 1.0 part by weight or less (excluding zero) (more preferably 0.05 to 1.0 part by weight) in terms of MnCOwith respect to 100 parts by weight of the main component. A piezoelectric element includes a piezoelectric ceramic body composed of this piezoelectric ceramic composition. Firing can be performed at a low temperature of about 1,100&#xb0; C. The piezoelectric element has a high Curie point Tc, can withstand solder reflow treatment, and achieves satisfactory piezoelectric properties.

Piezoelectric ceramic compositions and piezoelectric elements

A piezoelectric ceramic whose resonance frequency temperature characteristic can be easily adjusted is provided. It contains first and second parts (and) which can be alternately stacked layers. The first and second parts (and) are each composed of a compound having a bismuth layer structure, such as a complex oxide containing at least Sr, Bi, and Nb, and have degrees of c-axis orientation different from each other. Since the resonance frequency temperature characteristics change according to the degree of orientation, the first and second parts (and) having different degrees of orientation are appropriately combined so that the resonance frequency temperature characteristics of the piezoelectric ceramic () as a whole is easily adjusted.

Piezoelectric ceramic and method for making the same, and piezoelectric resonator and method for making the same

Anisotropically shaped ceramic particles are represented by the general formula {(KNaLi)(NbTa)O+aMeO} (where Me is at least one element selected from the group consisting of antimony, copper, manganese, vanadium, silicon, titanium, and tungsten; and b is a positive number determined by the valence of Me), where x, y, z, and a satisfy 0&#x2266;x&#x2266;0.5, 0&#x2266;y&#x2266;0.3, 0&#x2266;z&#x2266;0.3, and 0.001&#x2266;a&#x2266;0.1, respectively. The anisotropically shaped ceramic particles have a plate-like shape. The average particle size is 1 to 100 &#x3bc;m, and the ratio D/t of the maximum diameter D of a main surface to the thickness t in a direction perpendicular to the main surface is 2 or more, preferably 5 or more. Thus, anisotropically shaped ceramic particles suitable as a reactive template for preparing a crystal-oriented alkali metal niobate-based ceramic can be produced at relatively low production costs without the need for a complicated production process.

Anisotropically shaped ceramic particles and method for producing the same

A piezoelectric ceramic composition includes a bismuth layer compound containing at least Sr, Bi and Nb, e.g., (SrNd)BiNbO, as a main component and 2 parts by weight or less (excluding 0 part by weight), preferably 0.04 part by weight to 0.5 part by weight, of Cu in terms of CuO relative to 100 parts by weight of the main component. From the viewpoint of improvement in sinterability, 0.1 part by weight to 2 parts by weight of Mn in terms of MnCOrelative to 100 parts by weight of the main component is preferably contained. As a result, it is possible to obtain a piezoelectric ceramic composition resisting no deterioration in piezoelectricity even when a rapid temperature change occurs, and an advantageous piezoelectric component, such as a piezoelectric actuator or a piezoelectric resonator, manufactured using the piezoelectric ceramic composition.

Piezoelectric ceramic composition and piezoelectric component

A ferroelectric thin film device comprises an Si substrate; a TiN thin film whose Ti component is partially replaced with Al, the TiN thin film being formed on the Si substrate; and a ferroelectric thin film of an oxide with a perovskite structure formed on the TiN thin film, wherein the amount of Al atoms present at Ti sites of the TiN thin film after partially replacing Ti with Al is within the range from about 1% to 30% and the oxygen atomic content of the TiN thin film is equal to or less than about 5%.

Ferroelectric thin film device and method of producing the same

A ferroelectric thin film device comprises: a Si substrate; a TiN thin film epitaxially grown on the Si substrate in which Ti is partially substituted by Al; a metal thin film epitaxially grown on the TiN thin film; and a ferroelectric thin film grown and oriented on the metal thin film and composed of an oxide having a perovskite structure. The amount of Al substituted at Ti sites in the TiN thin film is about 1 to 30% in terms of Al atoms, and the oxygen content of the TiN thin film is about 5% or less in terms of oxygen atoms.

A three-component piezoelectric ceramic composition having a large electro-mechanical coupling coefficient and high mechanical strength, composed of xPb(Mg.sub.w/3 Nb.sub.1-w/3)O.sub.3 -yPbZrO.sub.3 -zPbTiO.sub.3, is adapted so as to place points representing the compositional proportions x, y, and z (x+y+z=1) on lines connecting points

Piezoelectric ceramic compositions

A piezoelectric ceramic which maintains a high piezoelectric property in a composition having MPB structure and has an excellent ability for stabilizing the resonant frequency is provided. The piezoelectric ceramic has a solid solution expressed by the general expression xPbTiO.sub.3 --(1-x) PbZrO.sub.3 as its main component. The value of x in the above general expression causes the piezoelectric ceramic to have a composition having the morphotropic phase boundary structure. A ceramic having a spinel type structure is dispersed within the structure of the piezoelectric ceramic. The amount of the ceramic having the spinel type structure existing in the structure is set at about 5 volume % or less. Co.sub.2 TiO.sub.4, Mn.sub.3 O.sub.4, Fe.sub.3 O.sub.4, Mg.sub.2 TiO.sub.4 and a ceramic having a compound spinel type structure which is a solid solution of them can be used as the ceramic having the spinel type structure.

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Omihachiman, Japan

Kosuke Shiratsuyu