The present invention relates to a ceramic comprising (or consisting essentially of) a solid solution containing Bi, K, Ti and Fe (and optionally Pb) which exhibits piezoelectric behavior.

A multilayer sintered body having alternately stacked Ni-based inner electrodes and piezoelectric ceramic layers. The piezoelectric ceramic layers contain a main ingredient of a perovskite compound containing Nb, K, Na, and Li, at least one element M1 selected from Nd and Dy, and at least one element M2 selected from Ga and Al. The element M2 content is 0.071 parts by mole or less per 1 part by mole of the Nb in a solution obtained through a dissolution process. This multilayer piezoelectric ceramic electronic component is manufactured through the cofiring of conductive films as a precursor of the inner electrodes and ceramic green sheets as a precursor of the piezoelectric ceramic layers in a reducing atmosphere in which the oxidation of Ni is inhibited.

The invention relates to a piezoelectric lead-free material based on bismuth sodium titanate, to a method for the production thereof, and to the use thereof.

The present invention can provide a lead-free piezoelectric material having a high piezoelectric constant in the room temperature range. The present invention for this purpose is a piezoelectric material including a main component containing a perovskite metal oxide represented by following general formula (1),
Ba.sub.a(Ti.sub.1-xZr.sub.x)O.sub.3(1)
where 0.02x0.13 and 0.986a1.02, a first auxiliary component containing Mn, and a second auxiliary component containing trivalent Bi, wherein an amount of the contained Mn is 0.0020 moles or more and 0.0150 moles or less relative to 1 mole of the metal oxide, and an amount of the contained Bi is 0.00042 moles or more and 0.00850 moles or less relative to 1 mole of the metal oxide.

A lead-free piezoelectric ceramic composition includes a first crystal phase made of an alkali niobate/tantalate type perovskite oxide having piezoelectric properties, and a second crystal phase made of an M-TiO spinel compound (where the element M is a monovalent to quadrivalent element).

There is provided a lead- and potassium-free piezoelectric material having a high piezoelectric constant and a satisfactory insulation property and a piezoelectric element that includes the piezoelectric material. The piezoelectric material contains a perovskite-type metal oxide having the general formula (1): (Na.sub.xBa.sub.1-y)(Nb.sub.yTi.sub.1-y)O.sub.3 (wherein x satisfies 0.80?x?0.95, and y satisfies 0.85?y?0.95); and at least one rare-earth element selected from La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, wherein the rare-earth element content is more than 0 mol % and 5 mol % or less of the amount of perovskite-type metal oxide. The piezoelectric element includes the piezoelectric material.

There is provided a method for manufacturing a ferroelectric thin film device including: a lower electrode film formation step of forming a lower electrode film on a substrate; a ferroelectric thin film formation step of forming a ferroelectric thin film made of a potassium sodium niobate on the lower electrode film; a ferroelectric thin film etching step of shaping the ferroelectric thin film into a desired micro-pattern by etching; and a thin film laminated substrate cleaning step of cleaning the substrate provided the ferroelectric thin film having a desired micro-pattern as a whole with a predetermined cleaning solution after the ferroelectric thin film etching step. The predetermined cleaning solution is a solution mixture containing hydrofluoric acid and ammonium fluoride, the hydrofluoric acid in the solution mixture having a molarity of 0.5 M or more and less than 5 M.

A piezoelectric material that has good insulating properties and piezoelectricity and is free of lead and potassium and a piezoelectric element that uses the piezoelectric material are provided. The piezoelectric material contains copper and a perovskite-type metal oxide represented by general formula (1): (1?x){(Na.sub.yBa.sub.1?z)(Nb.sub.zTi.sub.1?z) O.sub.3}-xBiFeO.sub.3 (where 0<x?0.015, 0.80?y?0.95, and 0.85 ?z?0.95). In the piezoelectric material, 0.04 mol % or more and 2.00 mol % or less of Cu is contained relative to 1 mol of the perovskite-type metal oxide. Also provided is a piezoelectric element that includes a first electrode, a piezoelectric material, and a second electrode, in which the piezoelectric material described above is used as the piezoelectric material.

A piezoelectric PTZT film is formed of a metal oxide having a perovskite structure including Pb, Ta, Zr, and Ti, in which the metal oxide further includes carbon, and a content of the carbon is 80 to 800 ppm by mass. In a process for producing a liquid composition for forming a piezoelectric film, a Ta alkoxide, a Zr alkoxide, -diketones, and a diol are refluxed, a Ti alkoxide is added into a first synthesis solution obtained by the refluxing, and then refluxing is performed again, a Pb compound is added into a second synthesis solution obtained by performing the additional refluxing, and then refluxing is performed again, a solvent is removed from a third synthesis solution obtained by performing the additional refluxing, and then, dilution with alcohol is performed, to produce the liquid composition for forming a piezoelectric PTZT film.

A lead-free piezo-electric porcelain composition which contains a main phase having voids and which is formed of a first crystal phase composed of an alkali niobate/tantalate-based perovskite oxide having piezo-electric characteristics; and a sub-phase containing a second crystal phase composed of an A.sub.2B.sub.6O.sub.13-based compound (where the element A is a monovalent element and the element B is one or more divalent to hexavalent elements). The sub-phase fills voids present in the main phase.