Aspects of the present disclosure relate to a piezoelectric device having at least one piezoelectric element, which has a support plane oriented to a force introduction element, wherein in the event of a thermal loading of the piezoelectric device in the support plane, expansion differences between the piezoelectric element and the force introduction element occur. To compensate for shear loadings, at least one transition element is arranged between the piezoelectric element and the force introduction element, the E-module of which is smaller than the E-module of the piezoelectric element in the support plane.

The present invention aims to provide a piezoelectric composition and a piezoelectric element. In the piezoelectric composition, the main component is represented by the following formula with a perovskite type structure,
(Bi.sub.(0.5x+y+z)Na.sub.0.5x).sub.m(Ti.sub.(x+0.5y)Mg.sub.0.5yMe.sub.z)O.sub.3
wherein, 0.05≦x≦0.7, 0.01≦y≦0.7, 0.01≦z≦0.6, 0.75≦m≦1.0, x+y+z=1 and the transition metal element Me is any one or more selected from the group consisting of Mn, Cr, Fe and Co.

A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than the rhombohedral crystal in a single composition, has a Curie temperature Tc2<Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a crystal other than the rhombohedral crystal in a single composition similar to the second component, has a Curie temperature Tc3≧Tc1, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the second component. When a molar ratio of the third component to the sum of the second component and the third component is α and α×Tc3+(1−α)×Tc2 is Tc4, |Tc4−Tc2|≦50° C.

Provided is a dielectric thin film including a metal oxide. The metal oxide includes bismuth, sodium, barium, and titanium, at least a part of the metal oxide is a tetragonal crystal having a perovskite structure, and a (100) plane of at least a part of the tetragonal crystal is oriented in a normal direction do of a surface of the dielectric thin film 3.

A liquid-ejecting head includes a pressure-generating chamber communicating with a nozzle opening, and a piezoelectric element. The piezoelectric layer contains a perovskite complex oxide containing Bi, La, Fe, and Mn and is ferroelectric.

A lead-free piezoelectric ceramic material has the general chemical formula xBiCoO3-y(Bi0.5Na0.5)TiO3-z(Bi0.5K0.5)TiO3, xBiCoO3-y(Bi0.5Na0.5)TiO3-zNaN-bO3, xBiCoO3-y(Bi0.5Na0.5)TiO3-zKNbO3, xBiCoO3-yBi(Mg0.5Ti0.5)O3-z(Bi0.5Na0.5)TiO3, xBiCoO3-yBa-TiO3-z(Bi0.5Na0.5)TiO3, or xBiCoO3-yNaNbO3-zKNbO3; wherein x+y+z=1, and x, y, z≠0.

The present invention aims to provide an excellent piezoelectric composition and an excellent piezoelectric element if the piezoelectric properties especially a high spontaneous polarization and a sufficiently high resistivity, the low pollution, the environment and the ecology are considered. In the piezoelectric composition, the main component contains the substance represented by the following formula with a perovskite-typed structure, (Bi.sub.(0.5x+y+z)Na.sub.0.5x).sub.m(Ti.sub.x+0.5yMg.sub.0.5yAl.sub.z)O.sub.3. Wherein, 0.01≦x≦0.8, 0.2≦y≦0.8, 0.01≦z≦0.6, 0.75≦m≦1.0, and x+y+z=1.

The present invention is a piezoelectric composition and a piezoelectric element using the piezoelectric composition, the composition being characterized by: having a Perovskite structure represented by general formula ABO3; being represented by composition formula x(Bi0.5K0.5)TiO3-yBi(Mg0.5Ti0.5)O3-zBiFeO3, x+y+z=1 in the composition formula above; and in a triangular coordinate using x, y and z in the composition formula above, having a composition represented by a region which is surrounded by a pentagon ABCDE with apexes of point A (1, 0, 0), point B (0.7, 0.3, 0), point C (0.1, 0.3, 0.6), point D (0.1, 0.1, 0.8) and point E (0.2, 0, 0.8) and which does not include the line segment AE that connects point A (1, 0, 0) and point E (0.2, 0, 0.8).

An actuator (100) powered by photonic energy comprises a rotor including a material (101) which deforms from a first underformed state when exposed to electromagnetic radiation to a second deformed state and begins to return to the first state when the electromagnetic radiation is removed. A stationary element (102) is affixed to the rotor. A moving element (105) engaging the stator at least when the rotor is in the second deformed state. Deformation of the deformable material in response to applied electromagnetic radiation is transmitted by the stator to the moving element by friction between the stationary element and the moving element for causing motion of the moving element.

A bender beam actuator includes a first layer of piezoelectric material and a second layer of piezoelectric material overlying a portion of the first layer of piezoelectric material, where a length of the first layer of piezoelectric material is at least 2% greater than a length of the second layer of piezoelectric material.