The piezoelectric composition is represented by the following Chemical Formula (1):

x[Bi.sub.mFeO.sub.3]-y[Ba.sub.mTiO.sub.3]-z[Bi.sub.mAlO.sub.3](1)

wherein 0.5x0.7995, 0.2y0.4, 0.0005z0.1, x+y+z=1, 0.96m1.04.

A sensor includes a first film, a first sensor portion, and a first element portion. The first film is deformable. The first sensor portion is provided at the first film. The first sensor portion includes a first magnetic layer, a second magnetic layer provided between the first film and the first magnetic layer, and a first intermediate layer provided between the first magnetic layer and the second magnetic layer. The first element portion includes a first piezoelectric layer fixed to the first film.

A structurally integral multilaminar planer device is provided where the layers are bonded without use of adhesive. The device includes a perforated metal plate and a transductive ceramic layer. The perforated metal plate and transductive ceramic layer are bonded by a conductive metal ink that is subject to a thermal cycle process.

Disclosed are methods, devices, apparatuses, and systems for poling a piezoelectric film. A poling system can be a corona poling system including a corona source with one or more corona wires configured to transfer a corona discharge onto a major surface of the piezoelectric film. The poling system can further include a grid electrode interposed between the corona source and the piezoelectric film. A substrate including the piezoelectric film may be supported on a substrate support, where the substrate and the corona source are configured to move relative to each other during poling.

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 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.

The present invention aims at providing a piezoelectric substrate with high joining strength between an electrode of the piezoelectric substrate. The piezoelectric substrate of the present invention is a flat plate-shaped piezoelectric substrate including a piezoelectric ceramic layer, a plurality of first electrodes and a second electrode disposed on one main surface of the piezoelectric ceramic layer, a third electrode disposed on the other main surface of the piezoelectric ceramic layer so as to oppose to the first electrodes, and a through-conductor electrically connecting the second electrode and the third electrode. The second electrode includes a connection portion connected to the through-conductor, and a small-width portion having a smaller width than the connection portion when the piezoelectric substrate is viewed from above. The second electrode and the outside are electrically connected to each other at the small-width portion.

A piezoelectric element includes first and second electrodes, a first piezoelectric body layer, and a plurality of first through-hole conductors. The first and second electrodes oppose each other. The first piezoelectric body layer is disposed between the first electrode and the second electrode. The plurality of first through-hole conductors penetrates the first piezoelectric body layer and is connected to the first electrode and the second electrode. When seen in an opposing direction of the first and second electrodes, the plurality of first through-hole conductors is arrayed in a matrix.

According to one embodiment, a sensor includes a first film, a first sensor portion, and a first element portion. The first film is deformable. The first sensor portion is provided at the first film. The first sensor portion includes a first magnetic layer, a second magnetic layer provided between the first film and the first magnetic layer, and a first intermediate layer provided between the first magnetic layer and the second magnetic layer. The first element portion includes a first piezoelectric layer fixed to the first film.

The present invention aims to provide a piezoelectric composition which is free of lead based compounds and is represented by the following formula (1), (Bi.sub.0.5xNa.sub.0.5xBa.sub.0.7y+zCa.sub.0.3y).sub.a(Ti.sub.x+y+0.8zHf.sub.0.2z)O.sub.3 (1), wherein, x, y, z and a in formula (1) meets the following conditions, 0.70x0.90, 0.02y0.28, 0.02z0.28, 0.90a1.10 and x+y+z=1. The present invention also provides a piezoelectric device having the piezoelectric composition mentioned above.