A piezoelectric element includes a first electrode, a second electrode, and a piezoelectric layer provided between the first and second electrodes. In the piezoelectric element, the piezoelectric layer is made from a perovskite composite oxide represented by Pb(Ni, Nb, Zr, Ti)O.sub.3 and the total of the Ni and Nb contents in the perovskite composite oxide is not less than 1 [mol %] and not more than 5 [mol %] based on a total content of elements contained in a B site.

Provided is a piezoelectric film that has a perovskite structure preferentially oriented to a (100) plane and that comprises a composite oxide represented by the following compositional formula: Pb.sub.a[(Zr.sub.xTi.sub.1-x).sub.1-yNb.sub.y].sub.bO.sub.3 wherein 0<x<1, and 0.10?y<0.13, in which in a case where a ratio I.sub.(200)/I.sub.(100) of a diffraction peak intensity I.sub.(200) from a perovskite (200) plane with respect to a diffraction peak intensity I.sub.(100) from a perovskite (100) plane, as measured by an X-ray diffraction method, is r, and a/b is q, 0.28r+0.9?q?0.32r+0.95, 1.10?q?1.25, and r?1.00 are satisfied.

An object is to cause a piezoelectric film to perform a piezoelectric operation at a higher voltage than the conventional piezoelectric film. An aspect of the present invention is a piezoelectric film, wherein a voltage at which a piezoelectric butterfly curve that is a result obtained by measuring a piezoelectric property of a piezoelectric film takes a minimum value is larger by 2 V or more than a coercive voltage of a hysteresis curve that is a result obtained by measuring a hysteresis property of said piezoelectric film. The piezoelectric film includes an anti-ferroelectric film, and a ferroelectric film formed on the anti-ferroelectric film.

A piezoelectric element including a piezoelectric layer having a perovskite structure including lead, zirconium, and titanium, and an electrode provided on the piezoelectric layer is provided. In the piezoelectric layer, in a range of 50 nm or smaller from an interface between the piezoelectric layer and the electrode in a thickness direction, a ratio c/a of a lattice spacing a in a direction perpendicular to the thickness direction and a lattice spacing c in the thickness direction satisfies 0.986?c/a?1.014.

Provided is a polymer piezoelectric film element which generates electricity at a high sensitivity upon vibrations across a broad frequency band, including those caused by the motion of humans or animals or faint contact stress, and those caused by automobiles and so on, which can be made into a thin film and at a high yield, and which can be used as a stably driving power supply device, a tactile sensor, or a vital sensor. The present invention pertains to: a polymer piezoelectric film element characterized in that an electrode sheet is formed on both surfaces of a polymer piezoelectric film, and by having a structure which has bumps and dips or a wave-shaped structure which has peaks and valleys in an axis perpendicular to said surfaces; and a power storage device, a sensor, or a vital sensor.

A piezoelectric element includes a first electrode, a second electrode and a piezoelectric film located between the first electrode and the second electrode. The first electrode is an electrode to which a relatively positive voltage is applied when the first electrode is driven, the second electrode is an electrode to which a relatively negative voltage is applied when the second electrode is driven, and a coefficient A obtained by the following logarithmic approximation formula in an aging test in which an electric field of 10 V/?m is applied at an ambient temperature of 80? C. is equal to or greater than ?4.200?10.sup.?2.

[00001]${?}_2=A?\ln \left(t\right)+B$ ?.sub.2: Schottky barrier height [eV] between the second electrode and the piezoelectric film when a positive electric field of 12.68 V/?m is applied to the first electrode t: Aging period [h] A: Coefficient B: Coefficient

An object is to provide an organic piezoelectric film with a high level of piezoelectricity and a high level of transparency. The organic piezoelectric film of the present disclosure has a total light transmittance of 90% or more, an internal haze value of 0.2%/?m or less per unit film thickness or an internal haze value of 4% or less, and piezoelectric constant d.sub.33 of 10 pC/N or more after heating at 110? C. for 10 minutes.

According to one embodiment, a liquid crystal layer is provided between a first substrate and a second substrate. A switching element is provided on the first substrate. A pixel electrode is electrically connected to the switching element. A color filter is provided on a liquid crystal side of the second substrate and corresponds to the pixel electrode. A common electrode is provided on a liquid crystal side of the color filter. A light guide plate guides laser light incident on a side surface and emits the laser light from a main surface. A diffusion plate diffuses the laser light emitted from the light guide plate and applies the laser light to the first substrate. A supporting unit supports the diffusion plate. A vibration generation unit is provided in the supporting unit and vibrates the diffusion plate.

A piezoelectric thin film element comprising a first electrode, a second electrode and one or more piezoelectric thin films there between wherein the first electrode is a platinum metal electrode having an average grain size greater than 50 nm and wherein a piezoelectric thin film adjacent the platinum metal electrode comprises a laminate having a plurality of piezoelectric thin film layers wherein a piezoelectric thin film layer contacting the platinum metal electrode comprises lead zirconate titanate (PZT) of composition at or about PbZr.sub.xTi.sub.1-xO.sub.3 where 0<x?0.60 and has a degree of pseudo cubic {100} orientation greater than or equal to 90%.

A piezoelectric element including an electrode and a piezoelectric layer provided on the electrode and having a perovskite structure including lead, zirconium, and titanium is provided. A radial distribution function obtained from an extended X-ray absorption fine structure of an L3 absorption edge of lead in an X-ray absorption spectrum of the piezoelectric layer at an interface with the electrode satisfies a formula (1) below

A/B?1(1)

(in the formula (1), A represents an intensity of a peak attributable to oxygen atoms closest to lead atoms; and B represents an intensity of a peak attributable to oxygen atoms second closest to the lead atoms).