Provided is a lead-free piezoelectric material having a high Curie temperature, a satisfactory mechanical quality factor, and a satisfactory Young's modulus, and a piezoelectric element and a multilayered piezoelectric element each using the piezoelectric material. The piezoelectric material contains 0.04 mol % or more to 2.00 mol % or less of Cu with respect to 1 mol of a perovskite-type metal oxide represented by the following general formula: (K.sub.vBi.sub.wBa.sub.1-v-w).sub.1-yNa.sub.x(Nb.sub.yTi.sub.1-y)O.sub.3 where relationships of 0<v0.39, 0<w0.39, 0.9w/v1.1, 0.80x0.95, and 0.85y0.95 are satisfied.

A piezoelectric material composition may be represented by Equation 1. A piezoelectric device may include a piezoelectric device layer including the piezoelectric material composition represented by Equation 1, a first electrode disposed at a first surface of the piezoelectric device layer, and a second electrode disposed at a second surface different from the first surface of the piezoelectric device layer.

[00001]$\begin{array}{cc}{a\mathrm{PbZrO}}_3-{b\mathrm{PbTiO}}_3-\left(1-a-b\right)\mathrm{Pb}\left({\mathrm{Ni}}_c{\mathrm{Nb}}_{1-c}\right)O_3+x\mathrm{mol}\%A+y\mathrm{vol}\%{\mathrm{BaTiO}}_3& \left[\mathrm{Equation}1\right]\end{array}$ where A is Fe.sub.2O.sub.3, Co.sub.2O.sub.3, Mn.sub.2O.sub.3, ZnO, GeO.sub.2, CuO, or NiO, and 0.15a0.24, 0.29b0.38, 0.30c0.35, 0.00x3.00, and 0.00y7.00.

A piezoelectric element includes a first electrode, a piezoelectric layer which is provided on the first electrode and which is formed of crystals of a composite oxide with a perovskite structure which is preferentially oriented in a plane, and a second electrode which is provided on the piezoelectric layer and which is formed of platinum which is preferentially oriented in a plane, in which, in the piezoelectric layer, plane intervals L.sub.1 of the crystals on the first electrode side are larger than plane intervals L.sub.2 of the crystals on the second electrode side.

To produce a ferroelectric film formed of a lead-free material. The ferroelectric film according to an aspect of the present invention includes a (K.sub.1-XNa.sub.X)NbO.sub.3 film or a BiFeO.sub.3 film having a perovskite structure and a crystalline oxide preferentially oriented to (001) formed on at least one of the upper side and lower side of the (K.sub.1-XNa.sub.X)NbO.sub.3 film or BiFeO.sub.3 film, and X satisfies the formula below

0.3X0.7.

Provided is a piezoelectric/electrostrictive film type element in which the film thickness of the piezoelectric/electrostrictive film is small, the piezoelectric/electrostrictive film is dense, and the piezoelectric/electrostrictive film has good durability and insulation quality. The piezoelectric/electrostrictive film type element includes a substrate, a lower electrode film, a piezoelectric/electrostrictive film and an upper electrode film. The substrate and the lower electrode film are fixed adherently each other. The film thickness of the piezoelectric/electrostrictive film is 5 m or less. The piezoelectric/electrostrictive film is composed of a piezoelectric/electrostrictive ceramic. The piezoelectric/electrostrictive ceramic contains lead zirconate titanate and a bismuth compound. The bismuth/lead ratio in the peripheral section inside the grain which is relatively close to the grain boundary is greater than the bismuth/lead ratio in the center section inside the grain which is relatively far from the grain boundary.

At least two types of dielectric materials such as oxide nanosheets having a layered perovskite structure that differ from each other are laminated, and the nanosheets are bonded to each other via an ionic material, thereby producing a superlattice structure-having ferroelectric thin film. Having the layered structure, the film can exhibit ferroelectricity as a whole, though not using a ferroelectric material therein. Accordingly, there is provided a ferroelectric film based on a novel principle, which is favorable for ferroelectric memories and others and which is free from a size effect even though extremely thinned.

Provided is a piezoelectric material excellent in piezoelectricity. The piezoelectric material includes a perovskite-type complex oxide represented by the following General Formula (1).
A(Zn.sub.xTi.sub.(1-x)).sub.yM.sub.(1-y)O.sub.3(1)
wherein A represents at least one kind of element containing at least a Bi element and selected from a trivalent metal element; M represents at least one kind of element of Fe, Al, Sc, Mn, Y, Ga, and Yb; x represents a numerical value satisfying 0.4x0.6; and y represents a numerical value satisfying 0.1y0.9.

Provided is a piezoelectric composition containing a major component that is a perovskite-type oxide which is represented by the general formula ABO.sub.3, which contains no Pb, and which has A-sites containing Bi, Na, and K and B-sites containing Ti. The Ti is partly substituted with a transition metal element Me that is at least one selected from the group consisting of Mn, Cr, Fe, and Co. The content of Bi and the transition metal element Me in the perovskite-type oxide, which is the major component, is 6 mole percent to 43 mole percent in terms of Bi.sub.u1MeO.sub.3.

A force-measuring device includes a first substrate, signal processing circuitry, a thin-film piezoelectric stack overlying the first substrate, and piezoelectric micromechanical force-measuring elements (PMFEs). The thin-film piezoelectric stack includes a piezoelectric layer. The PMFEs are located at respective lateral positions along the thin-film piezoelectric stack. Each PMFE has: (1) a first electrode, (2) a second electrode, and (3) a respective portion of the thin-film piezoelectric stack. The first electrode and the second electrode are positioned on opposite sides of the piezoelectric layer to constitute a piezoelectric capacitor. Each of the PMFEs is configured to output voltage signals (PMFE voltage signals) between the respective first and second electrodes in accordance with a time-varying strain at the respective portion of the piezoelectric layer between the respective first and second electrodes resulting from a low-frequency mechanical deformation. The signal processing circuitry is configured to read at least some of the PMFE voltage signals.

In an embodiment a piezoelectric component includes a piezoelectric layer having a polycrystalline piezoelectric ceramic material with a coercive field strength of at least 1.8 kV/mm and a carrier element to which the piezoelectric layer is arranged and with which the piezoelectric layer is mechanically coupled.