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 behaviour.

A method for forming deformation crystal twins in piezoelectric materials is disclosed. The method includes obtaining a crystalline piezoelectric material and deforming the crystalline piezoelectric material using a load. The method also includes heating the deformed crystalline piezoelectric material in an oxidative atmosphere to a predetermined temperature for a predetermined time to form a plurality of deformation crystal twins in the crystalline piezoelectric material. The method also includes allowing the crystalline piezoelectric material to cool to room temperature, and removing the load that induces the deformation of the crystalline piezoelectric material. Additionally, the deformation of the crystalline piezoelectric material is achieved by at least one of the following: compressing, stretching, shearing, torsion, and bending of the crystalline piezoelectric material. Further, the shearing creates a shear plane that acts as a twin boundary, which separates a plurality of deformation crystal twins with non-uniform orientation.

Material properties are manipulated using rapid pulse application of energy in combination with applied electric or magnetic fields. When sintering, annealing or crystallizing a target film, the pulse repetition cycle can be constrained to ensure material temperature rises above and falls below the Curie temperature before the next energy pulse. This process results in enhanced material properties as compared to traditional techniques having a single, slow temperature excursion and subsequent application of the applied external field.

A composite piezoelectric material, manufacturing of the composite material and use of this composite material in piezoelectric components are disclosed. More particularly, a piezoelectric thick film materials or piezoelectric paint being a composite piezoelectric material including piezoelectric particles randomly dispersed within a polymer matrix are disclosed. A paste of composite piezoelectric material including a matrix of polymer having a relative permittivity 3, normally 6, sintered piezoelectric particles having a relative permittivity in the range of 100-5000, normally in the range of 400-1000 and an average particle size between 1 and 50 m, although the particles should be smaller than 1/10 of the final thickness of the final layer of piezoelectric material, and additives such as dispersing agents or thinner are disclosed where the final paste has a 0-3 connectivity pattern, a content of sintered piezoelectric particles between 15 and 75 vol %, normally between 40 and 60 vol %.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particle include a core and a shell having a contents of bismuth higher than that in the core and covering the core; and the total area of the cross sections of the cores exposed to the cross section of the piezoelectric composition is expressed as S.sub.CORE, the total area of the cross sections of the shells exposed to the cross section of the piezoelectric composition is expressed as S.sub.SHELL, and 100.Math.S.sub.CORE/(S.sub.CORE+S.sub.SHELL) is 50 to 90.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particles include a core and a shell covering the core; the average value of the contents of bismuth in the cores is expressed as C.sub.CORE % by mass, the average value of the contents of bismuth in the shells is expressed as C.sub.SHELL % by mass, and the C.sub.CORE is lower than the C.sub.SHELL; and the number of all the particles comprised in the piezoelectric composition is expressed as N, the number of the crystal particles including the core and the shell is expressed as n, and n/N is 0.10 to 1.00.

A piezoelectric ceramic base body that has a polyhedral shape having shape anisotropy, such as a rectangular parallelepiped shape, and which has opposed faces on which external electrodes are formed. The opposed faces have first sides and second sides. Between the first side and the second side of one of the opposed faces, a width dimension of the surface in a direction orthogonal to the first side and the second side is larger than a length dimension of each of the first and the second sides. The crystal axis is {100} oriented in a direction parallel to the first and the second sides, and a degree of orientation by a Lotgering method is 0.4 or more.

The present invention comprises: a step of applying a liquid composition for forming a PZT ferroelectric film; a step of drying the film applied with the liquid composition; a step of irradiating UV rays onto the dried film at a temperature of 150 to 200? C. in an oxygen-containing atmosphere; and after the application step, the drying step, and the UV irradiation step once, or more times, a step of firing for crystallizing a precursor film of the UV-irradiated ferroelectric film by raising a temperature with a rate of 0.5? C./second or higher in an oxygen-containing atmosphere or by raising a temperature with a rate of 0.2? C./second or higher in a non-oxygen containing atmosphere, followed by keeping the temperature at 400 to 500? C. An amount of liquid composition is set such that thickness of the ferroelectric film be 150 nm or more for each application and ozone is supplied during UV irradiation.

A piezoelectric material includes a metal oxide containing at least Ba, Ca, Ti, Zr, and Mn, in which the piezoelectric material has a perovskite structure, in which: x, which represents a ratio of a content (mol) of Ca to A (mol) representing a total content of Ba and Ca, falls within a range of 0.10x0.18; y, which represents a ratio of a content (mol) of Zr to B (mol) representing a total content of Ti, Zr, and Mn, falls within a range of 0.055?y?0.085; and z, which represents a ratio of a content (mol) of Mn to the B (mol), falls within a range of 0.003?z?0.012, and in which the piezoelectric material satisfies a relationship of 0?(|d.sub.31(31 20u)?d.sub.31(?20d)|)/|d.sub.31(?20u)|?0.08, and has a value of 130 pm/V or more for each of |d.sub.31(?20u)| and |d.sub.31(?20d)|.

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.